I did a study. It included S-Flexes -E's, -F's and -G's. It included GT's AP-13, AP-14's and AP-15's. Go and look, but I'll just say that since then I have bought more GT's. I use them for case fans. I use them for heatsinks. I use two AP-14's on my D14, for example.

Do check in at Koolertek now and then. They are negotiating to get PWM-controlled 2150rpm GT's. Those will allow us to have GT's controlled by our PWM-only motherboards.