I am looking at a Garmin StreetPilot 2730 (older model discontinued). It still uses essentially the same mapping programs; however, the distinct advantage is it comes with a satellite radio receiver. I was planning to install a sat radio, so this is two pieces combined into one. Can't beat that with a stick.
There are newer versions of the GPS unit which also have the sat receiver, but they do not come with the GXM 30 antenna. Unfortunately, the antenna alone is right at $200. I have researched the antenna and it is my understanding that the GXM 30 is really the complete sat. radio system and just sends the information through the GPS Unit. Because of that, I don't think I can get a new model GPS and then add an inexpensive sat. radio antenna. The unit requires the Garmin GXM 30 Smart Antenna.
That having been said, the StreetPilot 2730 comes with the antenna so is worth the effort for me to find one. I am watching several of them on ebay right now, waiting to make a bid when the auctions get nearer the end. There is also a "buy it now" unit for $289. All else fails, that one will be mine.
I will most like buy a handlebar "Ram" mount for the unit once I get it. My intent is to hardwire it to the battery through the Garmin Motorcycle Mount kit. As an aside, the 2730 is also claimed to be motorcycle friendly by Garmin. It is supposed to be able to stand up to the vibration of riding and the rain.