Let me make a comparison....
I already have AT&T DSL Internet service.
They want to sell me a Microcell for $149
and charge me $20/mo to use the Cell on the Internet.
But wait, my iPhone already communicates through my Wireless AT&T Internet Router.
I already have Broadvoice for my home phone. $24.95/mo and allows me to also call 57 countries (UNLIMITED MINUTES). It's cheaper if I didn't have the International plan.
http://www.BroadVoice.com. Check out this page for iPhone Info:
http://broadvoice.com/support_installation_byod.html
And I added a Multi-Presence on my line. That allows me to use another device on my same Broadvoice Monthly Plan. (2 extra devices max). That was a one time charge of $9.95 and $2.95/mo. What did this do? It allowed me to purchase the Acrobits Softphone App from the App Store and use my cell on ANY Wireless Internet Connection OR 3G connection. Yes, it's like talking on my Home Voip phone, except I'm on my Cell Phone. And I can call anywhere in the 57 countries (non-business use) Unlimited with NO EXTRA CHARGES.
So, AT&T Microcell = $149 plus $19.95/mo
Broadvoice (if you already have it for your home phone) = $9.95 one time plus Acrobits Softphone $7.99 and $2.95/mo Multi Presence Broadvoice charge. And yes, this is UNLIMITED calling in U.S. and 57 countries International.
You be the judge on this one.