How well does ZFS work under FUSE?
I have no idea. zfs on linux [1] is a different approach: It's a kernel module, out of the official tree (due to the license issues).
FUSE should work as well, I .. just didn't try. So ZFS for me is now a ~normal~ kernel filesystem, with some caveats about the external dependency and ignoring the big 'solaris layer' it needs to provide before zfs even starts.
I use ZFS on Arch (although not on this laptop, actually). I don't think you _need_ to choose?