NonP, I've often listed Noah as one of the most beautiful/graceful/efficient and powerful servers ever! I would rank his flat serve among the fastest (I was once told his flat serve was recorded in the early 90's/late 80's at 140mph but have not been able to verify that). His slice serve, was among the top 5 I've ever seen. He had a pure slice in both the deuce and add courts, with little topspin component. Which meant big speed, and big break. His ad court slice down the middle was the best I've ever seen.
The only knock I have on him, was that his flat serve was very flat, so he had HUGE power, but a slightly lower percentage, which wasn't helped by his tendency to hit down. I think b/c of this, he had to rely on more spin serves, even on the 1st serve to keep his percentages up. His kick serve was also not great, partly because he started tossing futher to the right, as his career went on. I actually think this was more efficient, and improved his slice, but he got a bit less kick. Thus, his second serve wasn't all that fast, and didn't have all that much kick!
Nevertheless, what an absolutely beautiful motion, and when on, extreme power.