Wow excellent points. Actually all you guys are nailing both the strengths and weaknesses of these last 3 films.
I personally thought Kylo/Ben was one of the best elements (if not THE BEST) of the last 3 films but that's mainly because his character seemed to be the most conflicted and fleshed out, as opposed to others like Finn and Poe that either had alot to do or nothing. And yes, Driver clearly made his commitment to both sides and that's what sold it for me. He seemed to be very "method" in the fact that he became these people as he was filming, therefore that's why you see him do so well to change into Ben, and even worked with Ford to get it "right." He committed and you have to give him all the props. At the same time, I think he looked it as a new experience to grow as an actor and doesn't want to really do more than that. But I really hope he does a fun skit in SNL with Star Wars but maybe not. The Undercover Boss SNL skit as "Matt" is one the best things SNL has done in the last 10 years.
I have to do a re-watch of all 3 to see the progression. Personally I really liked TLJ because Rey and Kylo had a story that you could understand. To me, that was the one thing they brought to this film as opposed to alot of other stuff that they didn't.
I personally see the romantic connection to Rey and I think it was fan service to have them kiss but goodness gracious was Adam spectacular with the longing and finally, that smile. But again totally opinion on my part that it worked for me.
In conclusion, more Ben please.