because i never really trust microsoft, MSFS 2020 had alot of issues when it came to their launcher and updating BS, also i always keep auto updates off cause sometimes some updates break shit. anyways i'd stick with mojang for as long as possible.
So AFAIK, right now iris+sodium/fabric. Doesn't have support for PBR (being worked on) the latest public build has self-aware lighting feature added (i have it but the build hasn't been publically published) a mod gave me early copy of it, and the only thing missing is a menu to tweak shaders in game. Since you have to manually edit shader settings. e.g i had to spend 2 hours editing the LIB file inside the complimentary shaders to my liking..
Just started using it I'M AMAZED at the FPS gain and not to mention the stability!! the FPS is atleast twice as stable (less drops) very good (though setting up the complimentary setting through the LIB took my 2 hours (lmao) it was all worth it, HOPEFULLY we will soon have scene-awareness lighting (it'll be in the next build according to the devs) no ETA yet, and a MENU for shaders. Also they working on PBR support native xDDD it's awesome definitely worth it man! lots of more stability and FPS. great experience multyplayer/singleplayer with complimentary shaders (which should be an official default minecraft option imo lol)
WTF not really, i play java never played bedrock but both versions have ups and downs. E.G with bedrock you could average 300 fps with my rig with 32 render distance On java i barely manage 120 fps with 10 render distance.
Also like cod fish in bedrock have a 25% of dropping x2 bones on death but on JAVA cods have literally a 5% chance of dropping 1 single bone MEAL WTF :) get it?