Our company rolled out about 300 aircards to the field about 8 months ago and we have had extremely limited complaints. Most all are because they lose the aircard or break them. The units we have look like a thumb and plug
in to the side of the computer and if they get hit, they can bend or break, so they need to be positioned to avoid being bumped. They are simple to use and connect to the internet fast. When we tested them, we went with Sprint because the connections were faster than Verizon, but that could be different now.
We have located sales reps in remote
areas of the country and basically, if cell phone reception
is bad or non-existent, the air card will follow suit.
I believe we are charged between $40-$50 per month for unlimited service
and the connections are pretty good unless you are pushing or pulling a good deal of data (pics, music
files and especially videos). We tested one air card and had a user on a cruise ship
connection about 40 miles out of Miami
(but that was over a year ago and coverage could have been expanded by now).
I'm sure there are better experts out there than me, but thought I would mention my experience. Good luck.