I bought the Three. It's itty bitty. Concerning Resolution? I didn't buy it for that.
It's small. It's proven. It'll shoot way more res than I'll ever need to post to the web.
The GoPro Android app is pretty cool, too.If one is concerned with precise aiming, it is helpful to be able to see it on your cell phone screen.
It's not necessary, though. The lens is so wide angle that at any resolution it just has to be pointed in the general direction of where you want to shoot.
However, the thing crashes a lot. It doesn't want to delete videos that you've transferred off the card. Sometimes it doesn't even want to charge. It locks up if you are using wifi, and turn off the power to the camera.
The above issues I have so far been able to solve by removing the battery from the back and then reinserting. Still, irritating if one wants to ensure a full charge and empty card for an important run.
Battery life is limited to the hours you can count on one hand and if you're shooting in Hd, your memory card is gone pretty quick, too.
I can't tell you if that's any better between the Two or the Three. I didn't own the Two.
Overall? I bought the Three because I felt like I got a good deal on it, on Walmart.com, and I've seen nothing to lead me to think that buying the previous generation was better.
If nothing else, wifi is built in, the app is available and the camera is smaller.
Hope I helped.
