The ones in the corners.
Depends on the frequencies you want to trap. Although I'm skeptical of their product claims to go as deep as they state, I'm in no position to argue. The methods of measuring sabines for an individual trap have little to do with a typical listening position or overall effectiveness. It might be fun to have a shootout between the brands with a single microphone in the same room. Should the constraints be dollars or square footage? Would it be relevant? Probably not. It wouldn't be your room and your speakers.
The science of these is not complex, often misunderstood and, sometimes, misrepresented. What it comes down to is addressing your unique situation, which is the probably the least understood. However, no matter which brand or type, most who have just taken a stab at it have been impressed with almost everything, which seems to indicate it's all worthwhile.
