The Garmin Rino GPS is an upgrade from the etrex. The mic works great, it works great with my Motorolas and I can send my position to another rino user using the GMRS range.
In order to register with the FCC for the GMRS use just go to FCC.com. Fill out two short forms and pay a modest fee, which is good for five years. They will save you up a license and your call sign.
I have noticed that the Garmin Rino GPS works very well in dense leaf coverage because of its external antenna. This is a great product. I believe it so much I own two of them.
There is limited third party software to generate your own map, so perform an ongoing search for 'garmin custom map' through google.com
When I use the Garmin Rino GPS I noticed that this device is a great integration of GPS and FRS. The price tag may seem steep, but you must realize that the exact same GPS WITHOUT a radio (and the vibrator that is in the model) is about that price.
The features over the 110 are well worth the money. The Garmin Rino GPS as a basemap of North / South America, and 8 MBs of memory for downloading map data. It has a vibrator that will vibrate when you receive a call after about 45 seconds.