Best World Travel Mobile Broadband USB Card?

My picks for the 3 best World travel Internet access devices are as follows: 

All 3 work equally well Internationally.  The main difference is how they work here in the USA. 

Verizon:  UMW190

Pros:  Best USA 3G coverage, same International GSM coverage as AT&T and T-Mobile. 

Cons:  Highest cost for USB card itself

AT&T:  Velocity USB

Pros:  Free USB card and plan includes Free AT&T Wifi Hotspot usage

Cons:  Not nearly as good of USA coverage as Verizon, and slower than T-Mobile 

T-Mobile:  Rocket USB

Pros:  Free USB card, Fastest Card in USA (within HSPA+ coverage) and $10 less per month. Also includes free T-Mobile Hotspot usage 

Cons:  Limited USA coverage. Good in cities, poor rural coverage. 

Read my full article on World Travel Internet Access Tips. 

What are your thoughts?  What do you think is the best USA based Mobile Broadband card for world travel?