Jumps
Michelle has better jump technique than Sasha, though Sasha has bigger jumps. Sasha has attempted more difficult 3-3s (such as 3lutz-3toe and 3flip-3toe) but is generally not successful at them. I don't remember her landing a 3-3 in a competition - can someone correct me if I'm wrong. Michelle mainly just performs the 3toe-3toe, and has landed it successfully many times in competition.
I believe Sasha's one and only clean 3-3 was a 3lutz-3toe at 2003 worlds lp Rachmaninoff program (loved that program).
Jump wise, Michelle had far superior jump technique, steadiness, edge quality in and out of the jumps and even height was comparable if not better than Sasha's.
Spins and spirals I would give a slight edge to Sasha.
Skating skill Michelle wins, and artistry is subjective, I think both have great artistry, let's call it a tie, overall, I would still have Michelle ahead of Sasha as the better overall skater.