What are some components, gear, accessories, and so forth that might not make one faster on a bike, but still feels nice to have, forget the justification (i.e., treat yo'self)?
Common ones that I've seen bandied around are deep section wheels, low Crr race-quality tires, gold chain, anything with that oil slick anodized finish. Of course quality bibs and jerseys, but people have different fit and likes so no need to chime in brand names like Assos and the typical like (I'm probably in the minority of those underwhelmed by the Assos items I have).

I know someone will say oversized pulley wheels, but disregarding the price, do most people actually want them on their bikes?

Things I personally enjoy having as part of my cycling experience -- undeniably luxury upgrades over perfectly acceptable cheaper options but I appreciate having regardless -- are dual-BOA shoes, less flappy aero jerseys with longer sleeves that still have usable pockets, Oakleys, GP5k tires, a waterproof Rapha essentials case, and a K-Edge combo mount. And with all the rainy days we have in the PNW, all the expensive new rain gear is totally worth it to me.

Electronic shifting is a the top of the list.

Carbon wheels and the list goes on.

Also, there are plenty of other threads to debate about whether Thing X is a waste money or proof of elitism and whatnot. I hope that doesn't spew out here. Let's appreciate that there are some nifty things out there in our sport, and if someone has the means and wants to kick some cash* over to the people who make the nifty things, so be it, alright?

*: This person is not necessarily me, because believe it or not, I am an unabashed cheapskate.

Spot on. I have one Di2 bike that I bought because it was at a pretty great price, not because I specifically wanted it. I think I may again be in another minority subset of folks because it didn't spoil me from mechanical shifting, but it's one of those upgrades that would be difficult to tell people not to get if they could.

I've spent $$ on carbon bars that I liked the shape, SMP saddles, and high end shoes.

Power meter. Wheels I really like. Di2. Bike computer. (Watch in my case.) Handlebars that didn't come with the bike because I like these more. Carbon bottle cages because I wouldn't want to desecrate a nice frame with alloy ones.

Garmin's radar is a luxury I guess in the sense of not being common, but once you've used it a bit it feels like a necessity. I'm not sure if that makes the list or not, so there's its honorable mention.

I started looking for a new bike late last year specifically for electronic shifting....I have the deep carbon wheels on my Emonda already, so that was not a huge concern, but never had electronic shifting and I said screw it, I want it. So I got it. I love it.

I'd say a covert ebike is probably a "luxury" upgrade. It's hard to call it a "performance" upgrade because then you could justify any motor as a "performance upgrade" and end up with an eMoto. Which to be fair, many people do. But the spirit of the ebike is probably moreso to allow you to keep up with faster people who ride normal bikes and/or flatten hills so you can always hold a consistent speed and/or cover a greater distance.

Unicorn leather bar tape.

I wouldn’t call GP5K tires a “luxury” upgrade; the price of them isn’t astronomical compared to other tire price points, especially if you can get a good deal online. I’ve saved myself the price of several pairs of tires by NOT buying a carbon frame, though.

3-bolt road pedals are a luxury upgrade. A vanity upgrade even? Most cyclists who aren’t actually racing would get on just fine with recessed, walkable, 2-bolt cleats on our shoes, but I do love the engage chunk when I clip into my Keos...

I recently got a new (alloy, not carbon fiber) stem mainly for aesthetic considerations, so it is a semi-luxury upgrade.

I built a ‘pandemic project’ bike over lockdown last year, all the parts were slowly bought over the previous 2 years when I found them heavily discounted making the build quite cheap overall but decided to treat the bike to Favero Assioma Duos and F3 form Garmin mount

I've heard or read somewhere that MEILENSTEIN LIGHTWEIGHT WHEELS are the bomb! That would be a nice luxury upgrade.

In addition to some of the things mentioned previously, I appreciate my Silca Premio tool roll - the Boa retention system is nice when you have to access it. They just released an updated version and they also have a more conventional bag with a Boa, but I prefer the more old-school aesthetic of the roll.

Also from Silca, but not something that I own (yet) - I'd really like their Ti Torque set. Totally a luxury for the tool bag/roll, but also kind of needed with all of those carbon bits on the bike, right?

Ugh, I'd replace either/both immediately, rather than do without.

Something that's not needed but good to have is a decent portable bike work stand.

Your bikes that unreliable?

I'll toss my hat in to the ring for a power meter. Now that I have one, I really enjoy using it and seeing the results. But I know many other fast riders who get by just fine without one.

I've been known to work on a bike in the parking lot(or motel room) right up until starting a event, especially installing new bar tape. Another good thing to have is a portable multi tool that fits all of the bolts/nuts on your crankset. I do have roadside experience with that.

I also use one of these instead of Ziploc bags. Not needed, but good to have.

https://seatosummitusa.com/collectio...SAAEgILUfD_BwE

I'd definitely include power meter on this list. After getting addicted to Zwift over the winter, I'm now wishing I had one on every bike.

I'd also add:

• Chris King (or some other bling brand) anodized color hubs. Bonus points for getting the matching headset and BB.
• Carbon seat post, bar, stem
• Cycling specific sunglasses. Bonus points for interchangeable lenses.

Ahh, yeah. Aero carbon handlebars - can be a pain in the ass to install, but they look and feel great afterwards.

Rapha handlebar bag.

Having recently upgraded to a Di2 bike from one with 105 and then adding a cross/gravel bike with SRAM Apex, I definitely enjoy electronic shifting much, much more. I also love my deep section wheels, from the appearance and sound they make to some gains in speed (hard to truly say, but the Strava segments at similar power are consistently faster with the deep wheels). All that said... I love my Canyon cross bike, and won my group in a gravel race on Saturday with it. The shifting is not as flawless as Di2 by a long shot - it's not as nice as 105 was either - but the bike works fine, and I love riding it. It has nice, but shallow rim DT Swiss 1850 wheels that certainly didn't slow me down - we easily held 20+ on paved sections of the course. So, yeah, the wheels, electronic shifting and even the PM are luxuries, but I really do enjoy them.

I'm not sure I'd call a bike computer a luxury item: for those who either train or navigate, or both, they are pretty much essential. Ok, maybe getting a Garmin 1030, instead of the 830, might be a little luxurious, but for some the larger screen is an essential.

Id suggest mechanical Ultegra or Dura Ace over 105 is a luxury. Of course, Di2 means you have to go Ultegra as a minimum.

Id also agree with carbon bars and stem being luxury items.