Welcome Gil! I can't comment on the 522D's coupled with a sub, but I can say that overall, the Aperion offering is very musical. They blend the needs for HT and stereo into one speaker very well. I have listened to the PT's for 2-channel music and have been impressed with the speakers. I would assume, by principal, that the monitors and paired sub could render an even more musical image, but I will let someone who has that set up in their own home to comment on that...
The best thing I can say, is to get out there and demo as many speakers as you can, and understand what qualities in a speaker intrigue and please you. With Aperion's in-home trial offer, it allows you to compare it with others and really hear for yourself what they have to offer. I suggest you at least take them up on it, you really have nothing to lose, and I imagine you will be pretty impressed with what you hear!