All my vintage three mountain bikes are full rigid ones , one with its original full rigid steel fork, the two other withs a rigid carbon fork
Merida with its original steel fork

The Kona Kilaeua with its carbon fork

The Scapin Dedacciai with its carbon fork

During the rides I had with other mountain bikers,I rode much faster (especially with the Kona or the Scapin) than others who had full suspended bikes or those with a front suspension. My tires are 26*2.2 continentals on the Scapin and the Kona except on the Merida where I have 26*1.8 hutchinsons. My next mtb is going to have a front suspension and a steel frame.

georges1 Love the colors on that Merida, total 80s-90s style. It is what we need! No more boring colors bright and bold and screaming at you is the move!

Not true at all IME.

Indeed , the paint schemes in these years were outstanding. Despite it is road like geometry, it is a very nimble and fast bike. The XT 780 T is the best upgrade I have ever done on this bike alongwith the tubeless rims

I'm gonna neee to find a carbon fork for this Katai, when I can get around to building it. There's a guy around here with a Cignal I wish I could have.

Thanks to?

good components and my good legs

I'm sorry, but that was the answer I was hoping for because that wasn't a question that I asked. I put it in italics for a reason.

My favorite daily rider, is a full ridgid, an old 1990 rockhopper. have a 1995 as well, it's set up ridgid too, but I have the correct rockshox for it, like nit better without.
But then I have a fisher with a manitou fork and I love it, also have a Trek with a rockshox that I love.
In short, my point is, try it. If you were local I have a S&M Pitchfork you could try.

last night I decided that yes, I need a mountain bike

I've gotten rid of my hardtails and run a rigid (steel) fork on everything now. I love the weight savings and the complete lack of maintenance. Whether rigid is viable for you depends on the trails you ride, the kind of riding you do, the tires you use, and their air pressure. My hucking days are over, and I mostly ride woodsy singletrack or desert scree. Ledgy stuff can be a little jolting, but for those trails I use a 2.8" tire at about 16 psi, and it's honestly not a big deal at all. If I was still a competitive rider or lived in the Rockies I'm sure I'd make a different choice, but for me, rigid works.

cool, what bike takes the 2.8" tire?

Kona Unit X (2019)

My Surly 1 x 1 can take 26 x 2.8 tires or 27.5 x 2.4 which is plenty enough for riding trails. I am actually running 700 x 45 mm gravel tires on this bike right now and use my body as a suspension.

We have enough snow on the ground to warrant fat bike use right now, but also just enough that trying to ride a 29er would result in sliding out and crashing a lot.

Rode my rigid fat bike for 10 miles last night...With the lack of snow, a lot of the bumpy features that are usually under snow aren't buried right now...End up getting consistently getting busted in the balls by the seat. That gets old and reminds me why I don't ride rigid when I don't have to. Full suspension for the win.

Never had that problem. I spend a lot of time out of the saddle and stand on the pedals a lot when riding over roots and rocks and bumpy trails. When I stand up the whole body acts as a suspension and soaks up the bumps.

I get what you are saying and I try to do the same...but don't always "notice" every trail feature in time to get out of the saddle. Especially when riding at night and some of the features are buried under snow and leaves right now.

Also using my body as suspension for an extended period of time makes my arms, knees and hip joints hurt. To me riding rigid is the equivalent of removing the shocks and struts in your car and replacing them with a brick. Nobody would want to drive that car.

We are getting hit with a snow storm this week. All those bumps will soon be buried under a groomed trail.