I too was having the same issue. 3g going to 1X.
I flashed to
Calkulin's Rom and now I have 3g (icon shows EV) all the time and at minimum 2 bars. Before, it would swith to 1x. Now Opera, YouTube etc are very fast.
I have a Verizon TP2 but settings are for Spint. I only did the #228 and option 2. I even have more bars on the phone connection.
I am not a Chef, but it has got to be some settings that Verizon sets by default that causes this. Now, I am not sure if I should try other ROMS and loose this. I live in a very rural area but now all is well with 3G and signal strength. I am using the 23506 build.