I think ROTJ has some really strong moments, some of the best in the entire Trilogy in fact. But at the same time, it also has some of the weakest.
I agree with this assessment. The final space battle is simply wonderful, with some visuals that (IMHO) hold up really well even to this day. The speeder-bike chase was also pretty epic and really well done.
The Jabba plot at the start dragged a little at times and Boba’s demise was an anti-climax, but this opening section was otherwise ok with a good Rancor fight. I feel a little indifferent about McDiarmid’s emperor, although he was better here than in ROTS.
At the crappy end of the spectrum, what were they thinking with the ewoks… The whole battle of Endor plays out like a farce to me now, even though I enjoyed it when I was 8. I guess that’s what makes IV and V stand out for me: I enjoy them as much as an adult as I did as a child.