Watanabe's PRO lineup are darn fine knives - if you want to find inumerable comments, just expand your search using earlier start dates. Almost every 'old dog' on the three forums has had Watanabe knives at some time, and has probably reviewed then very favorably. BAck when I started on these forums (I think thats close to9 -10 years ago...?) there were 3 artisinal craftsmen...Carter, Takeda & Watanabe. I felt like Watanabe was the "IT" knife until people discovered you could get the ebony handle on the Takeda without having to pay the extra $15 or $25.
His standard knives are pretty nice too, with the trade off being rustic for value. I wouldn't mind owning a standard shiro uchi santuko in 210mm - I'm just not sure he would make it at the value price point.
Apparently the multi piece set is thought to be outsourced....
For all the good things Watanabe is, a few things that (IMHO) Watanabe is not...
His knives are not lasers - you will never mistake a Watanabe for a Tadatsuna. Doesn't seem to effect performance, if 'cutting' is how you measure performance.
He's not willing to do whatever YOU want, just to call it a 'custom'. If he thinks your request is for a knife thats too thin, or the wrong profile, or the wrong steel, or not up his ally, he will probably try to talk his way out of making it.
At the end of the day - seems like a cool guy, makes really good knives, and you have to love his little indicator that sometimes reports he's "hellishly busy"