Hi BerlinVet - I'm actually one of the Rockwell Instructors, so I'm not going to give you a sales pitch - I'm just going to relate one of my experiences with a Carbine 103 class I taught last summer.
The weather the first day was terrible - I mean terrible - but hey, we train in the rain, and so we had the class. We had about 3 inches of rain that day, multiple rifle failures during the day caused by the wet conditions, and all got thoroughly soaked to the bone. Everyone did pretty well, and we covered what we needed to cover. Several of the students had only signed up for the 101 portion, so we said goodbye and went home to dry off.
The next day, 3 of the 4 101 students were sitting at the gate waiting for me - apparently they enjoyed their soaking so much that they had decided before they were out of the driveway that evening to call in sick and come for the next day's class. The positive feedback was amazing.
I believe there's also a Rockwell review thread over on PAFOA's forum as well, have a look over there.
If you have any questions, just shoot me a PM and I'll be glad to answer them to the best of my ability - just let me know.