Further insight:
Do NOT work:
Huawei E173 (very recent model): doesn't even get a light
Huawei E353 (somewhat recent model): Gets a light, flashing green, but doesn't mount a mac disk to install, and is not seen as a connected device when I work thro network settings and install drivers manually.
Working OK
Huawei E1550: works great. Plug in and run install app.
Huawei E220 (very very old model): works, but see above post on installing drivers.
I further tried plugging a E1550 into a macbook, THEN testing the E173 and E353's - hoping it could be a driver issue - but no luck.
WOW, combine this inability to connect to 3G, AND the inability to connect to an external projector, and these new 2012 airs are a complete dud!! $10k wasted for my tiny little company!!!