I found someone selling the 512gb one for $240 and I’m debating on getting it. My other two options are a ps5 or series x. I personally prefer handheld gaming devices. I’ve owned an Xbox for years so I have several games. For the ps5, I heard it’s good but I don’t have any games which would be annoying buying a whole of new games. My current handheld devices are the 3ds, ps vita 2000, and switch.
The Steam Deck is my personal ultimate handheld. I wouldn’t want to miss it. You will get better graphics/performance on xbox or ps5 in many titles - no doubt. But I would guess you have a few games on steam and since you like handhelds - I’ve never felt more comfortable on a handheld before. But it is a bit heavy in my opinion for constantly holding it up. Playing in a state, where you can rest your hands on a surface works best.
Asking in the steam deck subreddit will most likely result only in arguments for the steam deck. But I owned every device you listed and only really miss the ps controller.