3-bet pre-flop or check-raise the flop?

Assume you are playing heads up and in the big blind against an aggressive button (Someone who raises 80% or more) or assume you are playing 3-handed in the big blind against an aggressive button (Some who raises 40% or more) when the small blind has folded. Also, assume you have a strong hand like AJ or better, 99 or better, etc. Do you three-bet pre-flop and take the lead in the hand or wait until the flop with the intention of check-raising unless the flop is terrible. Terrible being an A-K-T flop when you hold 9-9 for example. If the flop is 9-4-2 and I have AK, I am still check-raising. If you do favor 3-betting, why? If you favor check-raising the flop, why?

Some backround on why I'm asking. I've always 3-bet pre-flop in this spot with my stronger hands and never really questioned it. I sent an email to Matt Matros a while back regarding heads up and he mentioned in it that he didn't believe in 3-betting out of the big blind in a hu match. Recently, I've noticed some of the better heads up high-limit players never 3-betting pre-flop. These players are still in the minority as most high limit hu players 3-bet about 20% of the time but it has got me thinking....