Hey lonei....it's me again, lol. I do this sometimes and I have pics in my fotki under roller sets (you've probably already seen them though). I liked the results and it did get the roots really straight. I did 11 ponytails, one roller each. I find it easier and way faster to set in just one high ponytail w/ the ends rolled on really big rollers. This way you don't have to fool w/ parting and doing each individual ponytail. I do get different results w/ the one ponytail vs. the 11. It comes out perfect for flat ironing though, and it's simple and fast to do since you're looking for something to cut down on the actual setting process right?
Tip: that Beyond The Zone Stiff Head get my roots relaxer straight! I use this when I do the ponytail set and I was shocked at the results.