I finished the game. I enjoyed the story, but that was about it. Character interaction was really almost non-existant. The only time you really got to know your guys at all is if you went around the ship in between planets and said, "hi". Really nothing beyond that. I didnt notice any difference in peoples reactions to me based on being paragon or renegade. It never really seemed to matter. Overall i felt the game was a let down and the high reviews it got really werent justified.
First, it was relatively short, unless you went around repeating the same side missions on all the different planets. Honestly there was very little difference between the planents other than the color of the ground.
Second, you didnt seem to have any effect on your companions, you couldnt sway them on anything, they rarely actually had any input or opinions on a situation. Overall they had just a few things to say and that was it. Even the companions side storys were really boring and didnt really seem to develop the characters all that much. The romances felt rushed and completely out of place.
Third, The ability to truely feel good or evil, honestly there wasnt much difference in how you decided to go. I understand they werent going for a good/evil, but some kind of choices that would have changed the outcome of the game woulda been a welcome idea.
Now dont get me wrong, overall i enjoyed my play through, but i dont think it was deserving of all the praise it was getting. Kind of like how i felt about Fable, with just a few more hours of play tacked on to the end.
I guess part of my problem is i went in hoping for a KotOR type story/character interaction and it simply wasnt there. Im not a huge star wars fan, but i managed to play both of them about 4 times a piece, because things actually felt different on some of the play throughs, i didnt get that with ME.