So, here are my thoughts about On the Road.
Some details from the book are a bit blurry, so correct me if I am wrong at some point.
No need to mention, this all my opinion and how I feel about it. There is always room to discuss things

General speaking, it’s obvious that I loved it! The film gave me the same feeling as the book did, I even had to cry in the end. Fast paced, we were thrown from one situation into another but never did the focus on the characters get lost. Some scenes shot from inside the car, driving along made me feel like I was in the car myself. Very nicely done. Of course you can’t put a complete book into a movie, so there are a few things I’ve missed: the mexico part was a little short for my taste. It was told in just a few takes (or at least that’s what it felt like to me), so I won’t be surprised if people don’t get the ending when Dean mets Sal in New York for the last time. Also, the little boy leading them to the whorehouse, there was a lot more to him in the book. Something I couldn’t help but missind, even though this is weird: at some point Marylou steals a pot from Old Bull Lees house, which one of the kids used as a toilet before. Dunno why, but I missed that. And Dean giving Mother Paradise her 15 Dollars back wasn’t there. But that’s all ok, I never thought in the first place that they could actually get so much detail in it as they did.
So, now I’ll try and tell you what I thought about each of the characters.

Dean: Garrett delivers an awesome performance. I was a little surprised when Kat said she “never liked Dean”. To me, Dean always felt like a rather tragic character: raised almost without parents, gone the wrong lane, intelligent but a little unable to channel it, always looking for love and life everywhere he goes but all with a symathic site to it. The second scene in which I had tears in my eyes ,apart from the ending, was when Dean, Marylou and Ed arrive at Sals Christmas Dinner at his Sisters/Brothers/Aunts????? House. They are sitting there talking, Dean sounds sad, then he jumps up from the chair telling this wild story about a sexy night, gets back into the chair and says: it is nice having a family, isn’t it (or something like that). Garrett deliverd that with such an intense face and voice, I couldn’t stop myself. Sometimes I thought: boy, what did they make you take? Cos e.g. his dancing scenes were so wild! Awesome!

Marylou: I was amazed how well Kristen did. She have the character a lot of depth. One scene that stuck with me: they are in this car with two strangers and one sings this very sad song (btw, I want the sountrack!!) about love and family and that’s when this scene from the trailer with Marylou having tears in her eyes comes up. Marylou could have been played as a one sided, obsessive, young gal very easily but Kristen gave her a lot of maturity.

Carlo: as Conni already mentioned, he stood out. In the book, to me, he kind of went alongside everyone but didn’t leave an impression. His part felt like a lot more in the movie, which is cos of Tom’s face and the way he acts it out. It felt like so much more, I really did feel for him when he told Sal about the relationship he and Dean had.

Sal: first off, Sam’s voice is amazing. He should do audiobooks! Being the one observing, his part never got boring. Those times when he was in the spotlight, he held my gaze, I almost overlooked other characters.

Camille: as I mentioned in the dairy, I always had a picture of a slightly hysterical woman in my head. Kirsten Dunst changed that. Her portrayal of Camille made her a warm, likeable woman, and all she wants is to be with Dean and the two babies. You could tell there was a lot subtext in her performance, like why she send Dean away after Sal arrived. You could feel that she knew what would happen. And she knew both had to go on. She sends Dean away, baby Amy is crying, and Camille gets her work clothes on as if everything was alright.

Old Bull Lee: ROFL!! Really, I thought Viggo was so funny! Even though I had an even more mad picture of that character in my mind, Viggo did awesome. Not so much “mad behaviour” but what he said and his face! Amazing!

Amy Adams: 100% the character from the book! She nailed it! Period!

Steve Buscemi: I liked his character a lot more as in the book. Maybe cos I like his face generally, I don’t know. But he seemed less of an a****** to me. And to be honest, the sex scene, which wasn’t really one for me, with Garrett was funny to me.

Talking drugs and sex: it was all VERY toned down in my eyes. There is a lot more skin in the book, I can tell you that. Maybe cos I am german and kinda used to it, but there wasn’t a second when I thought: wow, that’s shocking. Even the whole drug-topic felt “less intense” as in the book. Yes, you see them smoke weed and take benzedrine and drink a lot but it was defintely toned down. Yes, the very first Dean Scene shows Garrett’s naked butt (!!!), but Kristen had panties on. And oh my good, yes, you see her boobs! No, not really shocking.

Final words, as Dean would say: yes, yes, yes!!!