I don't have one but have done quite a bit of research on them.
My boss is a big Raw-Foodist (people raw - vegan). He's tried to get all of us on the band-wagon. I'm not fully on board but I do enjoy some of his raw dehydrated treats and a co-worker bought a dehydrator as well.
My research indicates that the Excalibur ones really are the best ones if you are going to use it all the time - faster, dehydrate more evenly etc, some have a time, etc.
My colleague just bought one through Amazon, it's a round one rather than the bigger rectangular Excalibur. Not sure of the brand, but hers does the job although it took her three times as long to dehydrate one of her recipes than she anticipated. For the money savings (I think she spent just $29) she's totally cool with it.
(a.k.a. Lucky's & Sparky's mom!)