If your question is which program handles MIDI better then there is no contest. SONAR wins hands down! Acid has, I understand, improved its MIDI capabilities, but SONAR began life as Cakewalk which was originally a MIDI only sequencer. It hasn't forgotten its roots.
Of course, SONAR 4 hasn't been released yet. It's due the end of this month. Personally, I usually wait a few weeks/months before upgrading. I like to let one or two service releases come out before I jump since those usually repair the most glaring problems that seem to be inherent in most releases.
Ted