Phones differ in their ability to handle weak signals. Read reviews of
various models to see comments on how they compare.

The signal strength meter is a relative indication, and you should expect
no correspondence by comparing the readings on different phones, or even
different specimens of the same model produced at different times or with
different firmware.

Possibly.

Sure, but that can just as easily be a difference in how the meters are
calibrated -- there is *no* standard on what the bars mean!

The better phone reviews report on RF (radio frequency) performance.
Good bets are top end phones from Nokia, Motorola, and Sony Ericsson.

Dear Peter,

The signal strength coming to your handset is the same as coming to
another handset. There are various factors which make differences. The
receiving handset hardware and software also factors. If handling of RF
signal at handset side (H/W and Software both) is not in optimized way
then it may be cause of low RF (signal strength at handset). Perhaps
most of handset manufactures using same kind of H/W.
So you may find different signal strength at the same location.

Peter there is many other factors too. So you may find different signal
strength on handsets by same company with same operator sim.

Aloha
Saurabh