Well, while I've not been that lucky yet, I'd be pretty happy to try out hardware and review it in various places, primarily my blog. I do that already with hardware I buy. There's two possible situations though.
You're a professional reviewer. You have a stack of these things and happen to be a HWR regular. You have no real preference for any brand
You're a hardware enthusiast who happens to work for a company that makes stuff. You basically get to muck around with a product line so you know it like the back of your hand.
To me with 2, The standard disclosure thing works. For one tho, least ethics wise, would something like "I got one of these free from the manufacturer for review, and this is based on my experiences" be needed?