Cambridge Audio DAC Magic Plus (+ NAD C372) vs Cambridge Audio CXA81 - opinions please

Hello,

I'm looking for opinions on which gear would best compliment my speakers. I swap between a pair of Totem Sky towers and a pair of PSB Stratus Gold(i)s.

I currently send USB to an audio interface, then 1/4 to RCA from interface to NAD C372. I enjoy the sound quite a lot but I've been wondering if introducing a higher quality DAC could bump up the sound quality. My first thought was to Introduce the Cambridge Audio DAC Magic plus. 

A second thought was a new integrated amp with a built in DAC such as the Cambridge Audio CXA81. I have no experience with Cambridge Audio equipment so I'm wondering how the power section of the CXA81 would stack up against the beefy C372. I also wonder how the DAC in the CXA81 compares to the DAC Magic plus.

All I know is the DAC Magic Plus uses dual 24 bit Wolfson chips, and the CXA81 uses a single 32 bit ESS something or other... My uneducated initial thought is that the DAC Magic Plus probably a little better at doing it's job than an integrated counterpart but who knows.

I'd consider getting the CXA81 if the DAC is on par with the DAC Magic Plus, and the power section is an upgrade over the NAD C372 - Otherwise I'll just add the DAC Magic Plus to my current setup with a significant savings.

I have heard good things about Cambridge Audio... usually along the lines of "very musical" or something so I'm curious about how people feel Cambridge Audio amps stack up against NAD in general. If you have specific experiences with the CXA81 or C372 weigh in please.