I hardwired a deluo sirf star III in my car, (easily transported and hooked up to a cigarette lighter power) and I mainly use tomtom, latest versions of app and maps. typically pull about 10 satellite connections no problem.
I also have iguidance, google maps, live search, all work fine with gps, but tomtom's interface is something I've just got used to.
Here's the product page for the bt gps I use...
http://www.deluogps.com/prods_bluetooth.html