Mobile Broadband... AVOID!
Today, in certain areas, absolutely.
However, I'm not talking about today...
Truth is that there has been little advancement, or more specifically investment in data speeds or cell capacity for 7 odd years.
Most Operators paid huge amounts for the licenses, so it was not commerically viable to invest further in what was (at least then) untested waters.
Now that some have recouped a large proportion of their capital, it is pushing ahead now.
don't forget that there are many emerging countries where fixed line has a low adoption rate. The mobile Operators in these countries will see a much faster uptake and reap faster rewards. Products are already coming out now that are in effect mobile routers. Box on the dashboard of the car / bus / truck and a wifi signal broadcast to everyone onboard.
The new devices have better cell locking capability and cancel out the "noise" from neighbouring sites. Some also have dual carrier capability wich effectively doubles up your speed, and operators are also broadcasting on multiple frequencies from sites which improves capacity.
Give it 1-2 years and it will be like comparing dial up to Broadband.