Ill just throw some of my experience in here too (which is not much)
i brewed a pumpkin last year, it was awful. No real pumpkin flavor or spice favor. I used 1 tsp of cinnamon, nutmeg, allspice, and ginger, but put it in early in the boil. bottled with 2oz vanilla, no vanilla pulled through.
this year, i used this recipe:
steep 20 min .5lb biscuit
6lb Amber LME
1o East Kent Goldings 60 min
.5oz east kent goldings 10 min
4lb pumpkin pie filling, non-spiced, baked 45-60 minutes prior. 60 min
1 tsp irish moss 15 min
2tsp cinnamon 5 min
1 tsp nutmeg 5 min
1 tsp ginger 5 min
placed the 4lb pumpkin used for the 60 min boil (which was in a muslin bag) in the primary fermentor
4oz vanilla extract bottling
US-05
I will let you know in a couple weeks how it turns out. The hydrometer samples were good, so i have high hopes.