Personally I wouldn't mind stuff like the recomposits etc (provided they have the original starfields/backrounds etc).

I'd also like to see things like mattes fixed so you don't have those ugly green boxes around ships in some shots. (I guess that would've been less visible on actual film)

One pet peeve of mine has always been the redness in darth vaders eyes in some shots. Now I don't know if you could see that in the theathrical versions due to contrast/brightness differences. But it is rather inconsistent. Playing around with GIMP a little I found that if you desaturate the red parts of the eyes (and only the red parts) you end up with pretty natural black looking eyes.

I suppose for changes I don't "Mind" but stil wouldn't like to see fixed if possible. Stuff like the speeder blob.