I've cycle toured and backpacked with both iPhone and sport (waterproof, shockproof, etc.) cameras and the limitations have frustrated me by not being able to get a good shot of very important moments. (E.g. Had a Fuji Finepix XP70
mounted on my trekking poles when two California Condors flew over me at about 30 feet in the Grand Canyon last summer and the lack of zoom
frustrated my attempts to get a good shot.) For that reason, I've purchased a high-quality, long-zoom (30x), compact camera, the Sony HX-50V, that I think will be a good compromise between weight and capability. These compact cameras also take fantastic video as well.
Regarding the GoPro. My friend has taken the GoPro on weeklong cycle tours and backpacking trips and I've seen the amount of effort goes into keeping the batteries charged and memory cards allocated. He has focused on time-lapse video, which means the camera has to run for hours at a time and generates a huge amount of data. I personally don't think the results are worth the effort. Here's an
example from our bike tour of the Gulf Coast. I think a GoPro can be very useful due to its light weight, but I'd keep it exposed and mounted/at-hand for shooting full video at opportunities.