Again... I opted for the Garmin unit. I have the AIS 600 Class B transceiver. It's a really nice N2K compatible device and transmit/receive is a bit part of why I chose the 600. It's nice knowing where they are, but even better knowing that they know where I am.
Lot's of debate on the value of a transceiver over a receive-only unit, but that's for each to decide I suppose. Can't go wrong with garmin in my opinion. Very good quality and large support network in place.