Not entirely sure about the improvements between but you do know JXFS is from the same creator as SFS2; I've never had any problems with JXFS
I use SFS2 for my boot partitions and JXFS for everything else. I even format my ext USB 1TB harddrives as one partition with JXFS and it is quick and reliable I haven't made the move to anything bigger but I might try soon!
I always used the SFSFormat command and NORECYCLED, I'm not sure if that adds to any stability but it certainly stops this FS getting clogged at times with too many files in the delete cache. If you're worried about deleting the wrong thing just make sure you have SURE? enabled in DirOpus when you hit delete so at least you get that moment of recollection and pending doom that could save that odd file or directory, I have become exceedingly good at checking anything before deleting