I purchased this recently and I like it.
You won't get "new" sharpness on the blades, but it does give them a nice edge and it seems to be extending the life of the blades. I haven't tried this on extremely old or nicked blades yet. I first tried it on a blade that was getting dull and after about 30 seconds, it cut very nicely.
The one complaint I have is that it is L-O-U-D!!! I mean, really LOUD! This is louder than my vacuum cleaner. But, it generally takes less than a minute to sharpen.
I believe PatriceJ has also mentioned having one. Maybe she will chime in on how it works for her.