Since USB drivers are not provided you cannot connect the COM port (although it shows the option when USB cable is connected). I got the written confirmation from Huawei customer support that U5510 does not have USB modem or USB tethering functionality. Back camera is not so good, I doubt if it has even 2.0 megapixel whereas 3.2 megapixel is printed on the back. Phone lacks basic feature of importing contacts from any kind of file. Even blue tooth transfer is one-by-one and not in one go. So they have provided for manual entry of 1000 contacts....testing patience. There is a provision for creating shortcuts through Menu->Settings->phone settings->shortcuts but could not figure out how to use them. Forget software CD for PC sync and drivers, phone does not come with a proper user guide. Shortcut key (top right) and end-key squeaking from day one. Phone switches off automatically (with battery fully charged) in power-save mode while WiFi hot spot is active. Auto Power-on/off is useless as when phone auto-switches on it waits for your sim selection. When you are attending call on one sim you do not get call waiting tone for call on second sim. The caller gets "not reachable" message. Alarm rang everyday even if it was set for Sat and Sunday. FM/audio paused when Apps under internet services started. Could not add more SMS templates to the existing ones provided.
Phone display is good. WiFi hotspot works instantly. Good battery. Good Audio.
Lacks basic function of contacts import, no USB connectivity/tethering, no drivers provided