i use them. the sharpened edges don't last as long as the first edge does but it only takes a few minutes each time and i'm pretty sure the sharpeners have paid for themselves already. (the price will scare the beejeebers out of you unless you remind yourself how expensive the new blades are. LOL)
you do eventually get to a point at which you just can't get back a sharp enough edge to cut anything but paper. which is why i'm so glad June found the recycle place.
i find that by the time it needs sharpening, the blade and holder both need cleaning so it all gets done at once.
they're like most of the gizmos we can get. some of us love 'em. some will give you 72 reasons to avoid them like the plague. i plan to sharpen my blades myself several times before sending them to the recycle site to get new ones.