This is just a first glimpse review, I've only touched up a couple of chisels with is so far so how well I'll like it in the long run is still to be determined.
First up let me say I'm not sure if i have a sharpening stone problem or a (myriad of) solution(s), but I do like trying new things and so keep that in mind and I'll try to just lay out how I feel about this one in comparison to some of the other things I've tried.
What I bought was the Spyderco Fine 8x2 bench stone. http://www.amazon.com/gp/product/B000Q99RVI I've had some friends who have thier "sharpening system" for knives (and personally having always been mostly a freehand sharpener found it to be a bit gimicky but they like it so that's all good). I also haven't actually personally seen/held/touched any of their other bench stones, just the rod system (which I borrowed from one friend and tried out to see how it worked)
My primary goal for this stone is as a "finishing" bench stone for touch ups while working (something a bit coarser than compound on maple but capable of sharpening any of my tools which are a mix of high carbon W1/O1 and A2 steels - the latter of which is difficult to do much with on traditional stones). I haven't seen/tried the medium grades as bench stones, but the rod system seemed a bit slow when I tried them compared to some other options.
- Its hard! Its really really really hard. This means that I don't really have to worry about dinging it which has been a bit of a problem with the soft water stones (especially with.
- It wasn't flat. Measurably not flat, somewhat annoyingly not flat. I wouldn't buy this unless you have or are planning on simultaneously purchasing a diamond plate because there is no other way to flatten it. It took me about 15m with a 400g plate (the coarsest I have) to get one side usably flat and the other to have a flat in the center wide enough to use for small stuff (the whole stone was cupped a bit).
- I don't expect I'll have to re-flatten it anytime soon though because its really really hard (probably "never" for practicaly purposes at my use level).
- The edge is pretty nice, the finish off of it isn't quite as polished as off of the Sigma Select 13k stone (which is really nice), but its reasonably close and certainly good enough to take directly to a strop. I was able to take reasonable end grain shavings with a chisel that had been previously sharp but was starting get noticably dull on alder after about 20 strokes (I expect this to get slower over time unless I refresh the stone with a few passes on the diamond stone - I think as a finishing stone a bit slower would be ok).
- You can/should use it dry. This was a big selling point for me for ease/simplicity of use. I love the results off of my water stones but man they're messy.
- Its fairly slow, along the same speed as say a somewhat used arkansas black and certainly slower than any of my water stones. I'm ok with this for the purpose I bought it for but it should be viewed as something to be used near the end of a progression of stones for general use.
Overall I'm fairly happy with it at first pass. It seems like a decent solution for a finishing stone if you have a way to flatten it and need a finishing stone.