I've seen this question around here a lot, but nobody seems to have an objective answer and most of the answers i see say "why? you have SteamOS". So i put Bazzite on my deck and gave it a go. And now i'm here to answer my own question.

What it is:

If you want the marketing you can go to their website, but i figure the best place to start is what it actually is compared to SteamOS. The high level answer is that Bazzite is SteamOS adjacent, it brings a similar package with a few extras while maintaining the immutable nature of a console OS. The extras being an overlay system so your local changes aren't nuked with system updates, an up to date kernel and mesa (Within fedora's guidelines. so kernel is effectively rolling but no major Mesa updates unless during the 6 month release cycles) for those that want it now and not 12-18 months later. among others like boxbuddy and waydroid and a really handy emudeck installer combining this with easy tweaks to take it from PC to handheld ready. This makes the steam deck much closer to what say windows 11 would provide without having to compromise on extra spent battery or flashing windows to the SSD. This also brings wayland as well as many bug fixes to desktop mode, even the option for GNOME instead of Plasma for those who don't like plasma..... like me. While it is not necessarily good or bad, this also brings MAC in the form of SELinux to the deck. which makes security a consideration for the deck at long last

What it does:

What this does is have some minute configuration changes like a lower tick rate in the kernel which creates a system that feels more consistent and responsive, it doesn't net any additional FPS but reduces what can feel like sluggishness in some parts of the system and games. In the last day I have tested with GTA 4, Soul Reaver Remastered, Bomb Rush Cyberfunk, Far Cry 5, Stardew Valley, Moonstone Island, Dirt Rally (21015), Burnout Paradise Remastered and RE2 Remake. With the exception of GTA 4, the TDP was capped between 7 and 10 watts simply to balance battery and performance. mins and maxes did not change as it is the same hardware. video settings were the same as like when i used SteamOS i just let it set things to whatever it wanted. There is a difference in power draw and this is caused from a mixture of newer drivers and the tick rate explained above. With the updates and tweaks to the system some titles seem less jank than on SteamOS but this is not universal (exception being Moonstone island, but it performs the same as it does on my desktop PC now). Battery life is also slightly longer (we're talking minutes. nothing to write home about). and this seems to benefit heavier AAA games the most creating a nicer experience. also when testing it docked externally there is no funny business with resolutions and display mirroring or extending and both seems to work perfectly fine

What it doesn't:

There is no performance increase that can be backed by numbers in my testing so far. Battery life will still behave much the same as it would under steamOS, the only exception here is that kernel 6.10 and above does bring performance and power tweaks to zen 2 and 3 CPUs/APUs which the deck benefits from. this really only lead to a better experience in desktop mode coupled with wayland. the gains are negligible in game mode where you can directly tweak the wattage of the APU. so depending on your title, you can still expect between 2 and 12 hours if you are someone who tweaks the TDP for titles.

Why do this?:

You dont like Plasma and you dont always use gamemode. unless there are kernel tweaks the Bazzite folks are making there is unlikely to be any advantage over steamOS with the same configuration when it finally catches up. the same is to be said for Mesa. If you want up to date components and say GNOME on your deck. this has been incredibly rewarding. otherwise it's probably not worth the minuscule effort the install takes. Although if you are wanting to do this you will need a keyboard as Anaconda (the fedora installer) does not have On Screen Keyboard support for the deck. The short of it, if SteamOS is making your experience difficult because you want more and you want that bleeding edge experience, Bazzite on the deck is a great move. if you are indifferent to all this stuff, this mod is not for you.

I don't see me switching back unless there is a system breaking bug (the only bug i've seen is from desktop scaling but this was fixed with a reboot), but now at least there is an answer to a somewhat frequent question here. if anything drastically changes i may make a follow up post

EDIT: Clarified performance changes. This is caused by the kernel config and is not a straight gain, but more something where steamOS lags behind because Arch does. also way too hard to explain unambiguously.