I am one of the rare SW'77 and OOT fans, and here is how I have enjoyed the movies for 30 years. Because I saw each movie in the theater in its original release, I never was duped by Lucas that the story was written all out in 1975, so I watch each movie in context of how it was made, but I still enjoy the next installment with changes.
For instance, my favorite movie of all-time is SW'77, so I always watch that as just a standalone space adventure that has a true ending, and I get goosebumps EVERYtime I watch the medal ceremony as Chewy gets the last howl in.
Now I do love ESB, cause it is a great movie, and I watch that one in the context of a more deeper story then SW, where Vader IS Lukes father, and everything isn't happy go lucky like the first SW movie. I get a different set of goosebumps when I watch the ending with Luke/Leia watching Lando/Chewy pull away to save Han, you feel empathy for the characters and share in their struggle.
Now I do like ROTJ with warts and all, and sure Lucas tied everything up to end it all, but I do go with the story, and watch this one in the context that Luke/Leia are siblings, Han/Leia are a couple, and Vader saves the day at the end, but he is still not the MAIN person of the trilogy!
The problem with the PT movies, and why I have trouble adapting my OOT watching style, is you are watching everything BEFORE all the changes, so you can't take the story for what it is as a new installment, these ones lead to the OT, so you have to be on par with Lucas's changes, and thats where I get lost. I can't get over that Padme dies of the will to live, because in ROTJ, Leia says she remembers her mom dying very young?
I hope this makes sense to you guys, but I still say don't let the changes to the OOT affect you from enjoying that trilogy, cause even though SW'77 is my favorite movie of all-time, the OOT is my favorite trilogy of all-time. Yes, ROTJ could have been better, but come on now, it could have worse, it could have been Prequels quality!