Probably not!! If you think you might want to Jail Break your iPad (head on over to the hacking section to see what that's all about) then 4.3.3 is the only version that can be JB at present. If you update to 4.3.5 you can't JB.
There are no additional features in 4.3.5. The move to 4.3.4 was simply a move by Apple to patch the exploit that enable the iPad to be JB and the move to 4.3.5 was to patch a notional security hole in the operating system.
Tim