I have had a Zephyr for well over a year and can say it is a very solid bag blower. It's advantages include a nice valve system, very convenient bowl, lower temperature range than most competitors (all the way down to room temp) allowing you to use many lower temperature herbs such as hops. Some may have issues with the use of teflon like in the Herbalaire.
My only complaint is the needlessly bright display, which even remains bright red when in the off setting, rather than just, you know, shutting off. Also the gasket in the bowl portion will eventually wear out and need replacing.