The UF Spyderco is a mixed bag hone. Some
arrive from the factory with a saw cut surface that
needs to be lapped flat. Once lapped flat the surface
needs to be broken in... It may be coaxed to be better by
rubbing with a coti slurry stone or a spray of suspended
abrasive. They are hard and slow....
In hindsight my 12K Naniwa Super Stone was a better buy.
Especially when the price is equal.
The very hard Spydies are great when freehand sharpening
kitchen knives. You cannot dig a divot out of them like
you can on fine grain modern water hones. If you
sharpen both wood tools and razors the Spidie might be
a good choice.
EDIT:
Back to topic -- no worries if you get an eBay dog or two.
That is not the end of the world assuming the price is right. A lot
of very serviceable blades can be had for $15 and can
be brought to service with cautious hand sanding
and some time.