Hi Yjkimnada,
Yes, the 3A just does bass really well, and the bass enhancement control is extraordinary. Side note, from what I know about the the physics of the electronics you can add as much bass as you like without any fear of damaging the unit. Drivers can be blown, but by things like voltage spikes (also not a concern), not by using the factory designed bass control at whatever level.
As for comparisons with the PP6 bass, I'd stick by my earlier comments. With the bass control significantly engaged on the 3A at, let's say, midpoint (12 O'clock), you will have a consistently heavy bass regardless of program material. I totally agree with Alrainbow, the 3A was made for this. If what you want is that heavy bass all the time the 3A is the way to go, because you can't do this with the PP6. Once you start engaging bass boost on the PP6 it immediately announces itself as artificial. Also, because it's a two-step control you can't attenuate this to a satisfactory compromise between bass and naturalness. The 3A gives you limitless bottom end, and even at high levels it almost sounds like the work of a mastering engineer (that's high praise by the way).
Again, having said that, it is, nevertheless--added bass--so it obviously won't respect the program material. So if you want fidelity to the source the PP6 is better here, because to gain the same accuracy on the 3A you have to disengage the bass control completely and the sound gets a bit thin. The PP6 can remain faithful to the source recording while sounding full in the bass region. It is not weak in the bass, it's just program dependent.
So, as I mentioned, it comes down to preferences, if you consistently want to add bass to recordings that don't really have it the 3A is the way to go. That is what it's meant for, the PP6 cannot pull this off successfully. If you want fidelity to the source the PP6 engineers, in my book, have cut the right balances between lower-end fullness and accuracy.
Also, please do bear in mind that the bass region is the foundation to build the entire rest of the sound spectrum, but there are many other components that would go into deciding what is the right unit for you. Ah decisions, decisions, decisions....
All the best with your search for sonic bliss.