Referring to the Yamaha comment, Steve essentially said anything I would have regarding the company/build quality. There's also the point that ALL professional instrument from respected manufacturers have things to recommend about them. In other words, any pro player would probably find things to like about any pro clarinet, but he's probably going to prefer one more than any other. It's not that one is inherently better than the others; one is just better for him.
I just played a Cousenon. The first mpc I put on it was an older HS* and it sounded very nice. Then I tried a Vandoren M13lyre. If my only mpc was the M13lyre I would not want to play the cousenon at all. it was unresponsive and dull. The HS* made it sing up and down. Then you can vary your embouchure and throat to even vary the tone more.
Basically, it is best to somehow play the instruments you want to potentially buy before buying them. Simply because you never know if even the keywork layout will work for you, much less your equipment and playing style (as pete mentions)