Tom, I use the RF-1000 on a daily basis and have been very pleased with the purchase. I tried the X-eleven and decided the RF was plenty for me. The helmet is a little noisy, especialy with all the vents open. However, it sure flows a lot of air at speed. I ride in Souther MS with ambient temps at 95 to 100 degrees and 80 to 90% humidity...it does fine in really hot weather. There is no low res booming from under the helmet but I do get the occasional tea kettle whistle if the wind hits it just so. It is very light and holds up well. One warning, replacement shields are pretty $$$$.
