APR DP with other cat back systems

maybe this has been covered elsewhere but searching I could not find to much about fitment to a particular DP.
I have the APR DP and I was looking at cat back systems and im not sold on the apr system.
I would really like to know what people think of the other systems Borla, Remus, Magnaflow, and others. (I am really not sure what all the options are) One thing I would really like to know about is fitment and how good it is for each.
Will it bolt right up to the apr pipe without an adapter or will I have to take it to a muffler shop to have an adapter fitted?
As far as sound Im really not looking for something loud just a bit more.

I do wish akrapovic made a system they I would not even be looking around I would have made my choice.

Akrapovic does make a system!

I have the Akrapovic on another DP, they make one for the R too.
Its not the cheapest system but I love mine it should be pretty similar.


Remus is nice but the tips stick out way too much for my liking.

From my understanding, the Borla sounds great as a catback by itself. However, once you add an aftermarket DP, the thing is way too loud for most people.