A few days of mapping behind me and I must agree with those that say it's addictive. Also I'm starting to become impressed by what others around me are mapping. Someone reviewed the whole park near me last night!
I'm still trying to find a comfortable way to do my mapping. I find Potlatch easy to use, with good feedback and an impression of what the result will look like. JOSM provides more functionality, but lacks visual clues (it's only thin coloured lines and little dots). Also tried Mapzen POI collector and iLOE on the iPhone. The first is nice and easy to use, the latter does not seem to offer more and seems a bit more complex.
Did not have much need for GPS tracking yet, but tried Trails on the iPhone. I think that will be a nice tool for when I need to do some tracking.