Are they any good. The price can't be beat. About half the cost of a Whiteside bit. I am looking to get a spiral upcut bit for mortising and dado work, but have hesitated due to the cost. Holbren is offering a 3/8" bit with 1/2" shank and 1¼" cut for $23.00 less a 10% WN disc. Holbren 3/8" Solid...