With the special offer for only 12.79 (normally 15.99) you really could not do much wrong. Fits comfortably in hand, is working properly (they currently use Linux without special drivers). Battery life seems to be ok. Long-term testing is still pending, but with my old no longer quite fresh NiMH batteries it runs for a while now with no problems.
Not really convinced me only the DPI switching, the difference in speed is not really overwhelming (usually prefer fast mice and only occasionally a little more precision, if I have to meet her individual pixels).