they work great the only cons are imho they dont clamp on well to some designs of knives, the clamps can mar your finish,& also its a PITA to set it up, i had one for a while and ended up swapping it off, i use my sharpmaker a lot more, if i did a lot of reprofiling or a lot of heavy resharpening, the razoredge would make more sense for me, but i dont let my stuff get that dull to begin with.
it does get stuff sharp for sure, and helps ya to understand the basics behind freehand sharpening ie keep the angle correct.
oh, and if ya dont wanna mar your finish get some masking tape and put it on the blade and be carefull tightening things up, & IIRC only one of my knives didnt work well with the clamp, i dont rememeber now which one it was.
