Weaknesses: There is still more movement than I'd like. Don't get much improvement with doubling up.
Overall: The highest size I've found in any sport bra is G and I'm a GG so I usually have to compromise to accomodate that. This is the best sports bra I've found, but there's still a lot more movement than I'd like when doing any high impact work. Having said that, it's the only one I've found that works for me at all and I wear it for running and under my tri suit in triathlons where it's still very comfortable even after getting wet in the water!
Strengths: It's one of the very few that goes up to G. Good for gym work,not suitable for me for high impact work.
Weaknesses: Caused chaffing under the arm. Didn't find it comfortable to run in at all
Overall: Great that it goes to G. Personally I didn't find it a good running bra, maybe because my real size is GG and I had to compromise on size for that. They were squashed rather than fully supported. I'd happily live with squashed if they didn't move, but my whole chest, bra and all moved when I tried running in it. Resulted in nasty chaffing. Also didn't find it very breathable.