Actually just yesterday I helped with a test at a local studio about this. We used Slate FG-X, Voxengo Elephant, Limiter 6, and Ozone. We tested every algorithm as well. Our test method was to take several pro mixes, and crush them by -8db on each limiter. It isnt a real world example, but it really revealed some of the characteristics of the limiters.
For me Voxengo Elephant with the MAX algorithm won hands down. Even set at -8 on mixes that had already been crushed, it barely distorted the audio, and it brought up the percieved volume quite noticeably. Most of the others didn't even come close to Elephant on MAX, even some of Elephant's other algorithms. The FG-X set on Hard distorted like crazy, but it did add some interesting character to the low end. It sounded punchier.
After that test Voxengo Elephant is no. 1 on my list of plugins to buy.