Pearce Pros: Better road, no fees, easier shuttle. Can be done in similar timeframe as taking out at Diamond.
Cons: Not really much for good camps below Separation. Many people are ready to be done by the time you get to Diamond.
I personally like the night float and taking out at Pearce, and if somebody's going to drive my truck to a takeout, I'd much rather that be Pearce. It's not a smooth road, but it's much better than the DC road. If it's a full painless private where MOE, PRO, etc will be picking you up anyway, do Diamond.
Here's a good read if you're considering the Night Float option. Huck Finn Thread - Nightfloat
I've done it twice. First time we were early. I can't remember if it's cause of the high water (25kcfs constant on that trip), or if we just passed/left Separation early. I do remember finding the last 2 shooters on the trip on the barge in the dark, and we got to Pearce Ferry in the dark and slept before taking out. Second time we followed Brady's instructions pretty closely, and it got light about the time we got to Grand Wash Cliffs. That trip was a high flow experiment trip, but by the time we were taking out, I recall normal (10-14?) flows.