I've had a III+ for quite some time, and really like it. I just picked up a Vista a few weeks ago. I like the altimiter/compass feature, and it was one of the reasons that I bought it.
I'm somewhat disappointed with the receptions on the Vista compared to my III+, especially in a vehicle, or heavy tree cover.
The high-resolution on the Vista is great, but at the same time, it can be difficult to read. I'm still getting used to the screen navigation on the Vista.
I don't have any experience with the '76
