I got a handheld VHF. I didn't want to mount an antenna on my boat. I rarely use it anyway. I just have it case of an emergency. The mounted type units do have more power thus a longer range. I use my cell phone more than the VHF.
I have a handheld GPS too. I did buy a mount for it. This way I can take it with me in the car or another boat. The main advantage of the mounted type that I see is the screen size is much larger. The handhelds have a much smaller screen and less features.