I have the MFJ-1899T, a close cousin to the AX2. Like Mike said the magic is in the radials, as with all verticals. I mean, its a ground mounted, loaded vertical feeding it with 5 to maybe 15 watts. It works ok for a compromised antenna and certainly can be setup in minutes.
If you're operating portable and have the time and wherewithal, I'd consider an endfed dipole or a mag loop.
GL/73