No experience personally but buddy tried the fan. Didnt work for him. he went with ignites which seem to work. hes happy with them. I have a pair of Abom Heets I keep in the back pack for the days I need them and they are awesome
I've got a couple of the 509 fans and I like them, they do seem to help, but can become overwhelmed if you are really sweating.
The buzzing of the fan can also become annoying when stopped(cant really hear it when riding)