I'm most familiar with Mile 0 (Georgetown) to Swains Lock (just west of Great Falls). It is wide, flat, and should not be too muddy. If you have rain, this part of the trail shouldn't be too bad. Personally, I think the C&O is much more scenic than the WO&D, esp. around Great Falls, and you will be in shade the entire route. WO&D is in full sun. Plus there is a campground (Marsden Track) just east of Great Falls. Once you are in Georgetown, it is hard to bike all the way to Mile 0 -- towpath is interrupted in spots. Also, I highly recommend a side trip to Sheperdstown, WV -- a college town with great restaurants and a very short ride from the towpath. Have a great trip!