Is the move up to Parasound Halo A21 worth it?

Currently enjoying my B&W CM10s, Parasound A23 and P5. I really love the balanced, open sound that I'm getting from the current setup. However, there are a few areas where I'm seeking improvement. A wider soundstage and more engaging sound at lower than moderate volumes. And, a bit more bass, at any volume, won't hurt either.

I thought of moving up the Parasound chain to an A21, but I have no way of listening to an A21 prior to buying it. Has anyone else here moved from a 23 to 21? If so, did you think the move was worth the extra $$$$? Very interested in knowing what improvements people heard. And yes, I understand that room acoustics and treatments will give you a better bang for your buck. But, unfortunately, my setup is in the family room with very little flexibility. So it is what it is.

On an unrelated note, I was thinking of buying used (couple of current A21 listings here @ agon), but after you take into account shipping and paypal charges, the diminishing returns kick in. I'm struggling to see if net savings of around $500 (over a new one from audio advisor) is worth losing warranty, as Parasound warranty is not transferable. I'm sure these are highly sought after units and the premium is better than other comparative brands, but for me it's not worth the risk. So, I'm now thinking of getting a new one from audio advisor (no tax, no shipping charges) and have the peace of mind that comes with a full warranty.