See the tests this guy is carried out to highlight the problem:
The software used in the test is "network signal info"
Basically most of us are right hand users, this means we tend to hold our phones with left hand, so we can use our right hand to do stuff like typing, now the problem with the poor signal relates to the left lower corner of the phone where the antenna seems to be, when we hold the phone this way the 3G signal drops just like shown in the video.
The tests seem to indicate if you hold the phone with right hand (meaning you will not be covering the antenna area) that the signal remains strong.
Based on this understanding I came up with a working solution so the signal does not drop when holding the phone with left hand, which is to use the phone upside down & it actually works,
Just download an app called "display orientator" which allow you to setup the phone to display upside down.
I have been using the phone upside down since yesterday and it works great.
I've even been using Skype video calling and it works perfectly, nothing is up side down
Think battery life is also improved as signal remains strong & phone uses less power.
Just wanted to add one more thing there is an app called "phono" which shows an icon in the top notification area of the network you are connected to, and with the three uk network the signal when it goes weak simply drops onto the orange network which in turn appears as connect but kills your mobile broadband, maybe the three team are just not aware of how crap the orange service seems to be, so these 2 tricks should prevent you from dropping into the orange network & improve your signal.
Personally I don't mind to use this great phone upside down as it does not have physical keyboard.
Sent from my HTC One X using XDA