You really ought to get one in your hands and make your own mind up. I can't help you having either never played a Sandberg, or not recalling a time when I had a brief go on one. And even if I did, that would just be one data point - not really worth much, coupled with the vagaries of instruments in general - any factory can issue a Friday afternoon special...
Just because it's expensive doesn't mean it's going to blow your socks off either. I've drank disappointing 30 year old whiskies...
Well, that was just a total downer, so let's pick it back up - if you get hold of a BBP34 (either by trying it in a shop or simply buying it at distance knowing that you can send it back if it doesn't work out) and it does blow your hair back then you're right!