Is there any reason why my ipad has 2 bars lte and my iphone 5 cannot keep lte in the same room?

[bhs00]

I purchased my iphone 5 on release day and I purchased my ipad 3rd gen back about a year ago.  Both are on verizon service.  And both struggled at keeping an lte signal when i'm at work.  I work in a metal roof building and I assumed that this was the issue.  After several months I cancelled my service on the ipad.  Last week I decided to reactivate the ipad.  For some reason they decided to replace my sim card and gave me a new "phone number".  When I carried it to work, i've had 2 bars lte coverage constantly.  My iphone is still fluctuating from 3g to lte all the time.  Most of the time it is stuck on 3g. 

Is it possible that replacing the lte sim card in the ipad helped it get a better signal?  It doesn't really make any sense to me.  Has anyone else experienced a similar issue?