All but the PS version are now cross compatible, they’re all calls bedrock rather than pocket edition because they’ve all got the same updates and such.

The JAVA version is being phased out because Microsoft want you to go forwards and it’s easier to control their end and that’s why they make it a pain in the ass to mod in skins and such into the bedrock version.

Which version you should use it up to you, if you want the best version for play then you need to pick your platform, if you’re using a pc/laptop then it depends on your OS. I can’t use the Win10 version because I’m still running Win7.

I prefer the open modding and coding of the JAVA edition and that it tends to be ahead of the rest, this is the only patch / content update, aquatic, that has made it fall behind.

TL;DR : It’s up to what platform you use and what your friends use.