My biggest problem (so far) has been that my feet get a bit sore when I run in O' shoes frequently. I went 4 days in a row of running in O' shoes and my feet felt sore today. If I'm going to make it through all 31 days I'll need to make sure to sprinkle in some runs in trail runners (which is what I did tonight).
I'm worried about getting in an O' session on two days. One day is when we travel to the Georgia meet. I'll go to work then straight to the airport. The other day is when I'll be presenting a report to the City Commission - that could mean a long day. The easiest solution to both of these occasions would be to walk around on the downtown sprint map. But, can I legitimately count walking around on a sprint map as an O' session?
I say "Count it" so long as you put effort into it. Using an urban map you can still focus on keeping good map contact, checking off features, and maybe even some pace counting.
Of course, if you slack off and just stroll through the streets using the map as an afterthought, then you're certainly cheating!