I rate them as follows:
1. Structure Triax +16
2. Zoom Elite +6
3. Zoom Pegasus
4. Lunar Glide
5. Lunar Fly
Rambling stream of consciousness: I have noticed that Ritz is now wearing the structure, he was a life long pegasus guy and always injured... now he's in the structure and injury free. Rupp, Derrick, Erdmann, Kara Goucher, and perhaps some other pros also use the structure (although Derrick also wears the elites).
I have had the most success in staying injury free in the structure, although it sometimes feels a bit clunky, but other than that it's been a great trainer. The pegasus has also been good but the current ones (the 30s) aren't quite as good as the 29s (IMO) due to being a bit too high profile for my foot. Zoom Elite is a snappy somewhat supportive trainer that I've had limited exposure to but I have enjoyed it thus far.
I firmly believe NIKE makes the best trainers. Any other NIKE lovers out there want to weigh in their favorite trainers?