My husband bakes fresh pumpkin pies over the holidays and uses Splenda. By fresh, I mean, boil chunks of a pumpkin left over from Halloween, drain, cool, then peel. Refrigerate, and a day or two later drain the water that will accumulate at the bottom of the bowl, mash the pumpkin, measure, add spices, add egg, evaporated milk and Splenda. Sometimes he substitutes condensed milk for evaporated, and uses no Splenda in that case. Of course, condensed milk contains lots of sugar, so the pie is no longer sugar-free in that case.
If I were making the pie, I would probably try a combination of Splenda and brown sugar, which I assume might work somewhat better from a taste-and-color perspective. But that would defeat the purpose of a guilt-free pumpkin pie.
The Splenda-only fresh pumpkin pies are an acquired taste, IMO, but I have grown to prefer them to regular pumpkin pie. I feel they are more healthful, anyway, and I probably would find it difficult to readjust to the traditional canned-pumpkin, sugar-containing pie. Differences aren't really that major, but, yes, I think I truly prefer Splenda pumpkin pie now. But it was an adjustment at first.