First I need to say that this particular unit was still locked to the "3" network despite it being advertised as unlocked. Since it was a second hand unit and cheaper than new ones, I just decided to pay 4 euro using DC_unlocker and unlock it myself. Cheaper than returning it and buying a new one (which might also not be unlocked).
Having said the above, how does it work? Well, on XP, it will install its drivers and then you can use it on the "3" network. It is not easy under XP (or any Windows OS) to use it on another network even when it is unlocked. This is because the drivers and built-in software is locked to "3". However, for me this is no issue since my netbook has Ubuntu Linux on it. Since the built-in software does not auto-install, you don't have the same issue. Under Ubuntu 12, this device is simply plug and play since Ubuntu has built in drivers for it and the network manager application can configure the connection information you very easily in a "wizard" fashion. Hence, it is a doddle to use this on any network once unlocked. Another reason not to use Windows (Ubuntu is free as well by the way, give it a try).
The e353 has the newest chip set in it and it can achieve very fast speeds with good reception and where the latest 3G technology is available. For areas where reception is poor, the e353 also has an external antenna port that will allow for better reception.