I can't comment on the A300 but I have a CAP-151 driving my Magneplan 1.6QR's and I love it. The 151 is simple and powerful. I like the fact that most of the functions are on the remote (volume, source, mute, display dimmer, etc.).
The 151 does have a power-on delay of 20 seconds that some people might find annoying.
Good luck.
The 151 does have a power-on delay of 20 seconds that some people might find annoying.
Good luck.