Yeah. I got my iPad after apple stopped signing 4.3.3 so I can't downgrade if I don't like ios5
I think you are spot on there. JB brings to much.
I had to do a restore after Apple stopped signing 5.0 so am on 5.0.1 on my 4s which is nightmare after reading the devs are working on a jailbreak for 5.0 and have said not to update to 5.0.1
I'm pretty sure the jailbreak will work on both 5.0.0 and 5.0.1 since apple is fixing battery life issues and not patching jailbreak holes.
If you have a look under Kernel you will see Apple have patched the hole found by Charlie Miller in 5.0.
http://support.apple.com/kb/HT5052
Hopefully this isn't the only way to JB IOS 5.