That is one of the biggest failing of the PT is it was never funny. Whenever it tried it just came off as bad lines read by the actor. Remember in AOTC, when ObiWan is chasing Zam Weisel in Coruscant and Anakin goes to find a speeder, and when they finally catch up with each other, ObiWan asks him where he has been? Anakin says, "Oh, yo know, I was........." I don't remember the exact words Anakin said, but it just wasn't funny! Every attempt at humor in the PT was just forced and wasn't funny. The OT was very funny, mostly between Han, Leia, and Luke, it wasn't forced, and it was the first scifi movie that was serious yet hysterical too. That combo is the reason I love those three movies.
Anakin couldn't find one that he liked, or something along those lines. And you're right. Most lines that are spoken sound as if they were read from a sheet of paper (which is actually true, during ADR).
To get back to the original posting about the 'enjoyment' of the viewing experience when watching the PT and OT in the same orde as the Star Wars timeline...
Although I do not doubt it could be a different experience, I wonder if it would have been affected in any way if the Original Trilogy for Episodes IV to VI was used instead of the Prequels?
I think none of the alterations to the OT add much (if anything) to the story or the characters. Some additions gave us a little more information on the back story, but most of them are 'window dressing' and re-work of special effects.