I'm finally getting tired of all the bumps and potholes on my mostly flat commute. And i'm not buying in to the hype of the "do anything" gravel bike, whose greater tire capacity of a few C will solve all of my problems (currently using 32C). I do think that comfort technologies like suspension in the stem or seatpost will help. But i can't help think that i'm just beating around the bush with those options, and will be paying $5000 for a specialized diverge that would only give me a bit of front damping. I feel like i should just go all the way and get a front suspension or full suspension mountain bike for my route and get guaranteed comfort.

Has anyone made the switch from road bike to front or full suspension MTB for commuting and are happy with it?

Pneumatic tires are suspension. A 40 or 45c tire at 40 psi will have vastly more damping than a 32c tire run at 65 psi.

I don't like suspension on a bicycle... All of my bikes including my mountain bikes have a rigid forks. I use my body as a suspension. Bigger tires run at lower pressures also provide more than enough suspension to ride over rocks, boulders, bumps, roots, potholes and all kind of rough terrain.

When it comes to bikes I say go ahead and buy one. If it doesn't work out you can resell but still had the opportunity to ride.

Suspension is great for rolling over curbs and logs, but doesn't do a whole lot of good on bunches of small bumps or broken concrete. High frequency chop I call it. Full suspension would help with the deep pot holes, but you shouldn't be riding into the deep ones anyway.

Seatpost stems are another thing that I've never personally understood. I can see where it would be handy for the occasional surprise bump, but for the most part I have to wonder why people are riding full weight on the saddle through the rough? Just lift a bit and loosen your grip, let the bike take the vibration.

You do realize the cushier you make the suspension the more effort it will take to ride? Bigger tires really only help if they aren't inflated rock hard.

As someone who owns a full suspension mountain bike along with several road bikes I can say that my mountain bike is a pig to ride on pavement, just awful. And I am not talking about a cheap full suspension bike, it was a $3000+ bike when new. As well, Montreal has more than its share of bumpy roads compared to almost anywhere else I have ridden

Get yourself a Brooks Champion Flyer and enjoy the ride on your current bike. I don't have a full suspension bike and have ridden trails all over the country. I can't imagine needing a mountain bike for "roads".

A mountain bike on the street screams “nerd alert”, seriously its so 1980’s. Where’s my Klein? 🤣🤣🤣

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Sounds like you made your mind up and want reinforcement to support that. Get a full suspension bike and try it. It may by exactly what you are looking for. It's not for everyone. I get enough bounce just pedaling my XC hardtail even with the suspension locked out on asphalt sections from the tires alone to be annoying but that's me.

I ride a lot of gravel, equal to my paved riding. I've deduced that tire pressure, type, model, and size can and do make a HUGE difference in overall comfort and experience.

I pulled a late 90's era Schwinn Sierra from the garbage that had a regular fork but some form of a flexible stem, a suspension seat, and a spring based seat post. I tuned it up and gave it to a relative that still actively rides it a couple times a week. I've been on it a few times when fixing it and it is interesting. You don't need a $5000 bike to get some non suspension "suspension".

Only one way to know for sure.

Commuting is such a personal thing balancing speed, comfort, reliability and cost to your personal commuting route. There's reaction to the opinions of others too. Everybody is going to draw those lines differently.

buy it and ride it, then you tell us

If it absolotely does not have to be a mountain bike, consider a Dual Sport like Trek's 700c-37 tyre, + a quality suspension seat post

or a Moulton ..

Mtb's have long wheelbase compared to roadies, and a longer wheelbase means softer ride.
If you could get a hartail and put on SLICK high volume tires, that should be enough suspension without feeling like you're pulling Santa's sled.
But if you use KNOBBY tires, this will be a PIG!!! avoid.

Just make sure you get a XC mountain bike, not a trail, enduro, or - god forbid - downhill; XC geometry is better suited for riding long distances on flatter terrain, they are considerably lighter, and usually both front and rear suspension can be locked out.
And of course don't put knobby tires on it; there are plenty slick/semi-slick tires in MTB sizes.

A properly set up XC MTB doesn't have to be slow on pavement. I quite often see people on XC 29ers doing 20mph on roads; when racing that can go up to 30 mph.

There are trade offs, of course. I mostly ride around on road bikes. However, sometimes I would borrow my daughter's hard tail mountain bike. It was a gushy ride, but slow compared to the road bikes. Not sure what you have against a gravel bike. I have one and it is pretty nice for riding around the city. You get some advantages of a road bike, like multi hand positions and lighter weight. I have 700 X 35 tires and with the lower pressure they glide over most bumps. I would suggest you test ride a hard tail, full suspension and gravel bike. See which one appeals to you the most.

Suspension design is important. My YEti SB-95 (6" travel all mountain style bike with 29x2.4" tires) cruises quite capably on pavement - doesn't really matter if the suspension is locked out or not as long as it is set up appropriately for my weight

Its a 1x12 however and with a 30 tooth front ring, will run out of gear on a road downhill, but its top speed is still in 23 mph range

That said, for the type of action the OP is talking about, I am really enthralled with the Salsa Cutthroat -- gravel style geometry but with the ability to run 29x2.4 MTB tires itself

Get a 80s/90s steel 26" wheel rigid mtb off craigslist for $100 or less. Add 2" slick tires. Personalize with whatever tech-du-jour touches you feel like (Drop bar conversion! 1x drivetrain! Mudguards! Carrier! Long-tail conversion kit! Rattle-can paint job!) Get a hefty lock, and commute on it til doomsday.

Not worth it, to me. Try some wider tires on your existing bicycle. That's much less expensive than buying a new bicycle for a limited intent. Like you, I hated my 32mm tires. I switched them to 35mm Marathon Greenguards and it was all I needed to completely transform the bicycle (a Trek 520).

There are ~$30 suspension seat posts. THey are crap. I think Cane Creek still makes the excellent Thudbuster.

In the early 90s I used a Softride suspension stem on my MTB and I found, despite the drawacks, it was more effective than the rudimentary susp. forks of the day.

As said by others, full suspension bikes are generally unpleasant to ride on pavement for any distance. When the suspension is working hard over undulating ground you barely notice and it is an advantage, but when you can discern movement while riding on the road, it is frustrating and feels like you are being slowed down. A 29er with 29X2.3 or whatever would ride like a Lay-Z-Boy, but still be efficient on the road. A good quality 29er would also likely come with a decent suspension fork, which is not generally true of hybrids (poor suspension forks) or gravel bikes (usually rigid forks).

For me rougher road rides are best tamed with a good steel or titanium frame, really wide and more supple tires and maybe a little flex in the seatpost (granted I use the Thomson posts a lot and those are stiffer). Full Suspension bikes are excellent for mountain biking where I want to be on all the time but on the road full suspension is a lot of wasted energy bouncing around and honestly that ain't for me.

If I were to need more than that I would add a Kinekt seatpost and be in comfort city.

Sure, do it.

I have an opinion but this guy has experience, kinda like the difference between watching porn and having sex.......

Pull out your wallet and get a Moots YBB. The Routt looks especially sweet for the road. Maybe add a ShockStop stem if needed.

John