Pumpkin: mash, boil, or condition?

Ok, so it's a little late in the season, but I've decided to brew a pumpkin ale. I've done a lot of reading on the forums and seen a lot of recipes, but I haven't come across a good explanation of how to use the pumpkin (hopefully I'm not missing something obvious). I'm wondering what the best way to use the pumpkin is, and why. Should it be mashed? Added to the boil? Conditioned directly with the cooled wort in the fermenter?

Most recipes I've come across suggest mashing the pumpkin (but don't say why). Is this really necessary? I'm hoping for pumpkin flavor, not just to extract fermentables.

Other recipes say to boil the pumpkin. Is this just a technique for extract brewers who can't add it to the mash, or is there an advantage here? Will boiling give more or less pumpkin flavor?

Still others suggest roasting the pumpkin (fresh cubes or canned) and adding directly to the wort in the primary fermentation vessel. It seems like this would add the most distinct pumpkin flavor and aroma. Is this actually true? Am I missing something by not mashing or boiling the pumpkin?

A lot of people also say that pumpkin is not necessary in pumpkin beer at all, but even if this is true, I don't care. I want to brew with pumpkin! So, my question is--which way should I use it, and why? Thanks!

Pumpkin isn't even necessary really. We brewed a pumpkin dunkel this year w/no pumpkin. We were going to use canned pumpkin but there is a national shortage and there was one to be found. So we skipped it and opted for pumpkin pie spices instead. We used cinnamon, allspice, nutmeg, and ginger. Tastes exactly like pumpkin pie.

If you were going more for pumpkin and not pumpkin pie mash the pumpkin, but beware of a slow sparge. I'd probably roast it to caramelize some of the sugars for flavor. If you are gonna go for it go all out.