It's a large advantage. Defenses are always reactive, and when you have consistent mismatches that the no huddle will create, it's a large advantage. We should have our best playmakers on the field, and this will keep them on the field against mismatched defenses.
Your not creating a mismatch by simply using a no huddle, the mismatch most likey would have already been there. Teams are always trying to exploit mismatches, regardless of using a huddle.
Most player substitutions on defense are a result of passing situations like 3rd and long. You can stop a defense from substituting for that with no huddle, but if your offense has 2 or 3 WR, your not bringing in another WR on 3rd and long either.
I stick by what I said originally, the biggest weakness on the team is the depth at DT and CB. Those players wearing down in the 4th quarter will be a problem. Seems like a no huddle offense would get them on the field faster, unless Ainge is using up most of the clock calling audibles. We'll see.