Last week we stayed for 3 nights at the BWV and then 4 nights at the POLY...we walked to Epcot from the BWV everyday...took about 5-10 min tops...very easy walk...I would not walk to MGM tho...too far, esp in the heat...we walk to the Swan/Dolphin which takes about 5 min and then take the water taxi as it is the last stop before MGM...
as far as the Poly, it is very convenient to the MK, and that's about it...it seemed like everything else took forever, esp DTD...this was our first trip using disney transportation entirely, and I think that I will rent a car next time just to get to DTD each time...
depending on how long we waited for a bus (say 10 min avg), it took us a good 45 min to get to PI...when going to DTD, they take a back route, with the Marketplace being the first stop at DTD, and PI second...I am not exagerating when I say it took at least 45 min each time we went to PI...sometimes longer...
to me that is too much time...when you're scheduling a day where the theme park hours are already shortened, 2-3 hours a day of travel time in disney transportation is too much for me...