Pros: Doesn't seem to use too much power
Gets a GPRS signal anywhere
If you have the patience and the unlimited GPRS data plan (which is cheap these days), it will take you there for a third the cost of one of those UMTS modems. And without being tied to the carrier for a year.

Cons: Software a bit bulky. I like things you can fire up and go.
You'll have to enter the PIN number for your SIM every time you start the PC. (Not so bad really)
Could have used the bendable semirigid USB cable that came with the previous Solomon brand modem this seems based on.

Other Thoughts: I've done IRC, MSN and web browsing on this. Dial your speed expectations back and relax. It works to the limits of my GPRS all you can eat dataplan, which is the cheapest I could get.
I would have said don't expect to do online gaming with this, except for the fact that it works nicely for G**ld W*rs. Which apart from the trivia channels in IRC is the only gaming I do (and again it works!)

Bottomline: You only have GPRS, you need a data modem, get this and don't waste your cash on UMTS unless you need it. The phone call socket on the side is a nice bonus, but I have a phone for that (which curiously takes the headset that the modem came provided with)