The firmware is upgradeable so any bugs are ironed out pretty quickly. The main difference between the 2 and the 3 (I believe, without looking into it too much) is the built in wifi capability. I bought the add-on so have no reason to upgrade. There is no standard way of instantly viewing pictures after you take them but you can purchase an LCD backpack to fit on the back. I use the Apple
sd camera adaptor and an iPad to view if I want and I'll have a laptop with me on most occasions (the link is for the older iPad connector not the Lightning adaptor). You'll get a good hour out of the built-in battery, spares are available, and if you get the wifi adaptor it has a battery boost built into it.
The GoPro is an activity camera. It won't give you the best picture, true, but it will allow you to take pictures you normally wouldn't be able to. All you have to do is put GoPro into a
YouTube search to see just what you can do with it, there's some cool
Aquaduck footage like this. Is it worth the money? Well that can usually be gauged by how much you use something. I don't use it too much when I'm not vacationing, it's not the kind of camera you'd use in doors for Thanksgiving Dinner and the like! However it's one of the 3 cameras I'm planning on taking in the summer and you can get pretty creative with how you use it and mount it.
You should be able to get some good package prices on the Hero2 at the moment because of the introduction of the Hero3. I picked up some accessories from REI on our last visit to the US last November & there are plenty of internet options such as
Amazon.
Hope that all helps, it's not the cheapest, especially after buying all the extra mounts and attachments but as we say in England - "it does what it says on the side of the tin" and you're pretty much only limited by your imagination as to how you use it