I'm sorry your service sucks! I have the 4 and am quite impressed with the reception on the phone. I get service where others do not and where my 2G and 3Gs did not.Dont get me wrong and think I'm trying to say that you all are full of it, but those that claim "better reception" with the iP4, I just cant understand it.
Having said that, AT&T network sucks. My wife has a Pantek phone and drops calls everyday too. I hate when I drop calls, it's damn embarrassing and costs me time and money.
If you are having more drops than previous iPhones or other makes I'd take the phone back to Apple for a replacement. If that doesn't resolve the issue and if your service is mission critical, you might need a more reliable phone and network. Sorry.