The main issue is that SteamOS Beta updates frequently break Decky loader, but it's rarely an issue if you're on stable. The worst issues I know of with plugins were IsThereAnyDeal plugin was causing performance issues, and DeckyRecorder was causing some decks to be unable to switch to desktop mode.

Overall though it's rare to have serious issues from Decky, especially on stable SteamOS. You may not want to install a bunch of unnecessary plugins that you won't ever use, but you shouldn't hesitate to use any that meet your needs. If you ever have steamOS issues (crashing/etc) you will want to disable decky and see if that fixes it before you contact Valve though.

I have to be bit against decky. Out of the five steam deck crashes I've had past year all of them were because of decky frontend. At least that was what the crash report said and it had also option of disabling decky until next reboot. So my experience was decky crash -> no decky&happy -> system upgrade -> decky crash -> no decky &happy -> system upgrade... rinse & repeat

I'm not a decky (or steam deck) power user and last I checked the uninstall was not trivial so take my opinion with a grain of salt. I wish I never installed decky.

It’s a really good topic as I was also wondering if installing deckyloader would be worth it and if it would affect my Deck’s performance.