Although there are many things I like about Sonar I'm so used to using the keyboard to audition/move midi notes that unfortunately I can't use sonar for my editing midi needs.
Notice in this video you can use the up-and-down arrows to move the notes while auditioning at the same time. Also the left and right arrows can be used to audition midi notes from left to right or right to left.
http://www.youtube.com/watch?v=iX9M98yebwA Also the midi note dropout bug which happens when you're recording looped parts with input quantize enabled is a big drawback for me as well. plus the fact there is no auto merge of midi when doing loop/sound on sound recording.