I still have the free version 6, which is apparently not great for MIDI, though that's all I do with it at the moment.Doeas Ardour 7 have better MIDI support? Might consider paying the small price...
They also have a clip launcher now which is very cool. I just pay I think $3.50 a month, it's completely worth it. Have been paying that for about 6 or 7 years
MIDI definitely got better with 7.x, and I think 7.5 is supposed to have finished the refactoring they did on the tempo maps. Before, it was common for a note to not play if started exactly at the beginning of the bar, you had to nudge it a little bit.