On 04/01/2017 11:19 AM, Chuck Guzis via cctalk wrote:
  BGA, on the other hand, is something that I
haven't
 mastered--and I doubt that I ever will, given the small
 size of some of the parts. 
Yes, I'm with you.  if I get bad soldering on a leaded
flat-pack, I can poke the leads with an X-acto knife to find
the ones that wiggle, and then touch up the soldering and
test again.  With a BGA or leadless package, there's no easy
way to detect or fix bad soldering.
Jon