Here are some pictures with the GPS unit attached to the radio. You can see that, as expected, it adds some bulk to the radio:
At first I was concerned (from pictures I had seen) that the GPS bracket would cause a lot of stress on the mic connector and something would break. However, the Yaesu engineers thought about this and designed a bracket that installs in between the radio and the antenna and screws into the GPS. On one side, the base of the bracket slips into a little notch on the radio. This makes the GPS attachment very strong and will not compromise the integrity of the mic connector.
One thing I don't like is that the GPS bracket forces you to take off the rubber grommet that goes between the antenna and the radio. This rubber grommet is part of what helps with the water protection. You can see a close up of how the bracket and antenna fit together in this pic:
I guess having thing GPS attached to the radio in this manner is a little more convenient than having the hand mic attached. However, it does add a lot of bulk to the radio if you're going to carry it on your belt. I'm not sure whether or not I will keep it like this or just go back to carrying the hand mic. One thing that really stinks is that Yaesu charges you $30 for the bracket to allow you to attach the GPS to the radio. IMO, this bracket should be included with the GPS receiver.