yes the full size wheel fits ok. the front of the tire kinda rests on the cross member in front of where the donut is in stalled . although the front of the full size is lower than where the donut was it is still higher then the structure of the car and is protected. it is snug and does not bounce at all. id send a pic but cant hook my camera to my computer at this time.
According to the Pilot owner's manual, when you use your spare tire you should place the flat tire under the vehicle, in place of the spare. This leads me to believe that Honda has designed the spare storage are to accomodate a full-size tire.
IMO, the donut spare is another minor area Honda "cut corners" to keep the price of the car reasonable.