I know that Gidon has used them and found them to be good. He went to their Plymouth(?) branch.
They also do a mail order service which David (?), the chairmaker and writer, recommended. He said that he would order say, 15 cube and find ten that were really good. He said that this saved him all of the travelling, time and associated costs.
Neil's right - I use their Plymouth (Sasltash) branch for nearly all my hardwood. I think they're pretty good - they will help you sort through the wood - no matter how much you want. They carry a good selection - although mainly imported from America. And their prices are good (Although worth getting their price list - the lady who takes the money seems to price according to how she feels which unsurprisingly bugs me.)