Yeah, I definitely think how much you value this controller is directly proportional to how much of the full Steam Deck control scheme you use. As a heavy user of the Deck's touchpads to the point I'll never consider another handheld without them, this is still a day one purchase for me even at $99, but I'm not going to recommend it to anyone without huge caveats.

The Ultimate 2 Gyro works on PC too, at least on the Wireless version.
Update the dongle and controller firmware via the 8BitDo App then hold the B button when turning on the controller. Steam can make use of the Gyro and extra buttons directly.

I never use the capacitive touchpads on my SteamDeck

Only in desktop mode when I don't have my full docked setup with real keyboard and mouse. They are IMO better than touchscreen when everything is so small (and the Deck is too heavy for holding it in one hand for a longer duration).

Same. My Gamesir Cyclone 2 is so great. I don't use the track pads at all on the Steam Deck. The 4 customisable back buttons would be useful, but not for £85. I have yet to figure out what good motion controls are in game with any controller.

But if anyone else is looking flto buy a controller this does look like a solid option.

That's totally fair, I think to me it's definitely worth it. Even just for being able to have input parity with the deck so I can use the same control scheme. I personally use the touch pads quite a bit too and set them up as menus for some games. You can do some pretty cool stuff with them

Do you play first or third person shooter games? if you do you should give setting up the gyro a real go of it. I configure mine to only turn on when holding down L2 (aim down the sights) and it works so damned amazing compared to just thumb stick aiming for shooting stuff. Especially sniping or compensating for full auto weapons raising up. I liked using it so much on my steam deck that I had to go buy a PS5 controller to use for my PC just to get the gyro. Setting it all up correctly on your steam deck is a bit of a pain to tweak just how you like it, but well worth it. So much fun using some clapped out sniper rifle in a borderlands game with gyro aiming.

I have the 8bitdo Ultimate 2 and I'm still gonna get this (eventually, once I get a gaming PC), because the dpad is pretty bad for precise 2D games. And the back buttons don't gel with me as nicely.

The main problem is that I'm using it for waking Switch 2 and I doubt the Steam Controller could do that, but if it's easy to customise, someone out there might make it work. If that's the case, instant buy.