Well, I'm new to the forum, but not new to GPS in my boat. I've been using them for about two years now. I've got a Lowrance 332c at the console, and a 334igps on the bow.
I wouldn't be on a lake I didn't know without them, they sure help to find what you are looking for as well as the way home at the end of the day.
Additionally, I use the 334igps (which has an internal GPS antenae) in my truck when traveling to lakes I haven't been to. I've got a RAM mount on the dash as well as on the front of the boat, so it's easy to move. With the Lowrance map create software on my PC, it's easy to create a map and route to a new area, load it to the 334 and then navigate my way to a new lake. It made it easy to get to Lake Fork back in Feb, and then it was nice to have the GPS to navigate this lake for the 4 days I was there.
As for being dependable and repairable, the jury is still out. The 334 had to go back to Lowrance due to an internal GPS antenae issue when I first got it, but that took less than a week and they paid for all the shipping. My biggest issue with both of these is that the software sometimes hangs and the unit has to be reset (this is done by pressing both the Ent and PWR buttons at the same time when turning the unit on), which is a pain as all of your custom settings are then lost.
I like the sensitivity of these units though. While drop shotting at TR, I can see my bait and watch the fish come up to it, then set the hook.
btw, I'm headed to TR tomorrow night for 4 days of fishing - not particular as to what I catch, so long as I catch something...
Tom...