Well according to the guys over at silentpcreview, they reviewed both the 3700AMB, 3700BQE and the sonata. This is what they had to say at the conclusion of thier BQE review.
"Between the 3700AMB and the 3700BQE, which would I choose? It depends.
* If I didn't want to mess with cutting out the grills I'd go with the 3700BQE.
* If I wanted the best "turnkey" Silent PC case I'd go with the 3700BQE.
* If I was willing to mod the fan grills myself and was going to replace the PSU and case fan with the quietest versions I could get, I'd go with the 3700AMB.
Between the 3700BQE and the Sonata, which would I choose?
* The 3700BQE, no matter what. It breathes better so it'll run cooler at the same noise levels, it's roomier inside and it costs less money than the Sonata. The one thing the Sonata has going for it is the front Firewire port, but that's not much of an obstacle to work around in order to start with a better case."
So according to them, the BQE is the way to go.