I bought one today, after checking as many alternatives as I could.
I'd rather have a 4G version, but that didn't exist at a similar price.
I have 90 days to return it if I don't like it.
The hotspot came with a bonus 3gb/30 days, which auto-loads when I finish the first card. It shows in the account as a refill waiting.
I bought the $10 card for my initial purchase, and chose 500mb with no expiration (vs 1gb for 30 days.)
I suspect that this will carry me almost to New Year's Day.
My planned use is mainly in the RV when the campgrounds have the (commonly) pathetic weak public wifi.
My other options are to
a) try Foxfi with my wife's gingerbread phone, since Sprint has ICS locked down, or
b) ~Pay~ for the tethering add-on and have it turned on and off over and over, or
c) choose a more expensive plan, maybe with 4G. (Don't like that option.)
I'll know more within a week or so - we'll be trying it out at a Rally in Daytona next weekend. Hold my beer - I'm going in.