I have no experience with the Avatar and can't find any specs on their site, but I'd be willing to bet that the CN212 is louder. It's only lighter by about 10lbs, which is significant to some. The form factor is also very different, and I personally like the CN rectangle vs. the B212 cube.
The CN212 is the best cab I've used. It's got a great tone, it's reasonably small, very light, and stupid loud. IMO it would be a nice upgrade.
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