"Best" is a word that makes me grit my teeth. I leave it to sports fans.
"Best" is what's best for your needs, and even then, you're talking about a moving target. I have used the location services of both Android and J2ME and both have been easy to work with and did the job well. Android has the advantage that the location sensing API is part of the general sensor API, whereas JME requires a separate API, but either way, they're only usable if the target device supports GPS. Blackberry IS J2ME, at least in all the few cases I'm aware of.
Customer surveys are for companies who didn't pay proper attention to begin with.