I realize this is many years later, but you'd still think he'd be able to put up more of a fight against Vader than THAT, considering what we've seen him do with the Force before.
I might think so, if Episode VI had been made after Episode III was in the can. But it wasn't.
There are many ways that the PT doesn't match up with the OT. I found the Emperor's death satisfying in 1983, and I still find it that way today, even after seeing all the whiz-bang of the PT.
Sometimes "less" is more. ROTJ still manages to be better than at least 2 of the 3 PT films, and it's a toss-up comparing it to ROTS. On the other hand, ANH and TESB are hands-down better than all of them.