[citation][nom]dannyaa[/nom]... calls do not drop if you just "touch" the spot. Maybe if you have a negative -121db signal, yes. But your Droid X won't even make a call at -121db. I can hold the phone in a death grip all day and not lose signal.[/citation]
Anandtech even stated that it loses about 19db from holding it normally, which is about 2x as much as other phones. So if you have anywhere below about -94db and you will likely lose the call assuming as Anandtech did, -113 is the worst possible signal strength you can maintain a call with.
So just because you can hold your phone all day and not lose the signal, doesn't mean other people with a weaker signal won't lose their calls. There are plenty of areas and scenarios that would cause your signal to drop below -94db and lose the call just from holding it. You probably won't lose your signal in a city, but rural areas with fewer towers that are farther apart are likely to have the most issues.
It's great that it holds calls better than other phones when not being held and all that, but this problem pretty much eliminates that advantage.