In my opinion, the 4 is better for ease of use but the quality is nearly identical to the 3. The 3 is easily the better value for the money. I have the 3(black) and have not even thought of upgrading mine. Well at least not until they cam out with the new one, the small GoPro Session. But I still think I will wait.
Others will tell you to go with the 4 simply because of the touchscreen LCD, I disagree with their logic.
Others will tell you to go with the 4 simply because of the touchscreen LCD, I disagree with their logic.