Which style of defense would you prefer and why?
I think it's best to do whatever the rest of the league isn't doing, and that it's irrelevant what it is.
The 3-4 teams are succesful now because less people are doing it and it's something different to prepare for. First, during the dome patrol era, the 3-4 was great because it was unique. Then everybody started doing it, and it wasn't so magical, so everybody went back to the 4-3.
It started getting unique again, and more teams started doing it. The cycle is due to repeat again shortly.
You have to run what works for your personnel, but that aside, I'd like to run whatever everyone else isn't running so that we're something different to prepare for.
The talent in the NFL is so similar from team to team; scheme is the most controlling factor, I think.