Don't worry, unless you're in a really marginal 3G area, it's just your phone. I only use 3G (and WiFi) of course and it works fine.
One thing I wanted to mention is the Verizon Network Extender...even though it galls me to pay a princely monthly sum for Verizon coverage, and then have to pay $250 to actually extend Verizon's coverage to my house in a way that doesn't quickly drain the battery of my phone, it makes my phone much less annoying *smile*. Without the network extender, we have one bar of signal strength at my desk, and up to 2 bars elsewhere. One bar of cell phone strength causes the phone's battery to drop quickly, since the phone is working hard just to keep the cell phone signal usable. And not enough 3G to do much of anything. With the network extender we have at least 3 bars of cell signal strength throughout the house, and good enough 3G to actually use the internet, etc. reasonably. Although I'm usually using WiFi at home, a lot of visitors just continue to use their 3G, and it's good to have some *smile*. So, like I said, even though it bugs me to have to buy an appliance to get the coverage that I'm paying for, I'd recommend it if you're in a "fringe" area. Saves a lot of charging and annoyance.
By the way, my address shows on Verizon's map in a "best" area *sigh*. If this is the best, I'd hate to see the "good" areas.