I've had good results with my pumpkin ales but I've never actually used real pumpkin. I've used squash which is still a gord but with actual flavor and another time with just the spices. Both were quite tasty! I just make a good red ale recipe and add the spices with a tincture made with spiced rum and then soaked the nutmeg, cinnamon, ginger and sometimes cloves. I add the tincture to the keg.
I normaly do 10 gallon batches so I split it in half add the tincture to one and dry hop the other also different yeast normaly an english strain for the "pumpkin" and american for the dry hopped one.