I used a Brickwall (Zerosurge) for a short while and found it limited dynamics and soundstage compared to going directly into the wall. The same with a Tripp Lite. The AQ Niagara 1200 worked the best with my older gear until I got my Technics integrated and CDP and again, after trying it out of boredom, found that going directly into the wall was best.
All the best,
Nonoise