I'm not doing great financially at the moment, so just dropping $600 on a new gaming system is a big ask. Hence why, before the holidays this year, I'm still very curious about what people think of the SteamDeck, and if anyone has used it, as well as any other handheld gaming PCs (I know that's not really that common, but I'm gonna' ask anyways).

1: I'm a millennial. My favorite game, to this very day, is still Halo. Unapologetically. I STILL play Halo MCC at least once a week. I play Halo Infinite a little less than that, but I'd still like to be able to play it (the multiplayer AND the Campaign). Do these games work well on Steam OS right now, or would I still need to dual-boot into Windows to get any meaningful gameplay out of them?

2: I know it looks like it plays very well, but how are the ergonomics in a practical sense, not just a "have to make sacrifices on a handheld" sense? Like, I know I can just sync a controller to it, but I'm wondering if it actually feels somewhat comparable to a controller in the hands, as far as comfort and whatnot. I've had a Switch since launch, and recently got the NitroDeck for it, but the right thumbstick is... in a terrible position. It's waaay too low.
Basically, does it feel really nice to hold, and how does it compare (if anyone knows) to other handheld gaming PCs?

3: I know there's a way to "boost" the performance of the ROG Ally with an external GPU, but is it possible to get something similar for the SteamDeck at all? Any kind of hard-mod even?

Listen, I know a lot of this can be found in some way on YouTube, but most of the time, it's the most brief of snippets, or youtubers being very broad or extreme with their opinions and views, so it comes off as unreliable. I'd rather hear what people who have actually had long-term hands-on with the thing have to say. Example: I can't find a "Halo" related video that isn't months old, or just goes, "I tested the multiplayer, but I don't know about anything else," etc.

Sorry if this all seems, like, by the numbers annoying crap. I'm just wanting a gaming machine.