I am on my third Samsung Galaxy Nexus and my fifth SIM card.
My signal strength is typically between -100 dBm and -110 dBm. Occasionally I will see -93 dBm.

Does this mean that all or most android phones have terribly antennae, or does it simply mean that they use a different scale on the dBm meter.

Several years ago Dish Network changed the signal strength meter so that what used to be 100 to 110% signal became about 50 ot 60%. Could this be what is happening with 4G?