Belles Reference 150A or Reference 350A?

I have been putting together an upgraded system -- after 3 years in Tokyo (where you couldn't play music loud enough to enjoy it) I'm now building a listening room. I have a Belles Reference 150A -- I can't really tell you how it sounds because my B&W 802D's arrived with 2 broken tweeters... Buy, I have been looking at the Belles Reference 350A.

Can anyone out there comment on the difference? I using an Audio Research preamp -- should I step up to the 350?

Thanks for your 2 cents.