I've used a couple of Garmin units along with the Uniden GPS unit. Probably the most important thing to consider if you choose something other than the Uniden GPS, is a means to keep it charged while travelling. The Garmin units I had operated with batteries that did not last as long as my trip.
If your plans are only for scanner applications, I'd suggest the Uniden GPS. If you do other things, such as hunting/hiking/boating and would use the GPS for that, then the Uniden won't do you much good.