I own the 3/8" version from them.  I have done fairly scientific
studies on it, a generic 1/2" Taiwan, and a pro 3/8" and 1/2" clicker
as well plus the new rubber handle 1/2" Sears clicker.  All clickers
are relative but letting off immediately at the click usually gave
results within 10% error for the Taiwan, 5% for Sears, and 3% for the
pro wrenches.  I think they are a fine value.   All get bad when used
low in their ranges as it is hard to feel/hear the click plus they
funtion more erratically low in the ranges.  Frankly I would buy
the 3/8 and 1/2 from Harbor for less than the price of a Single
Craftsman for occasional use as then you would have wrenches appropriate
for both low and high ranges.

My opinions only.
John
ja@coe.wvu.edu (who now owns 2 said pro wrenches from auctions and
                doesn't really care anymore)