I try to remember to cup my hand around the bottom of the phone, and create a "tunnel" from my hand to the mic. Sometimes this helps. When I don't do this, I get the "I can't hear a thing you're saying" comment practically every time. Having the mic on the back of the phone is not a great idea.
When I chose the Spec...I went off of a few reviews, and the specs. It looked like it would be one of the faster, more powerful phones on the market at the time, that wasn't $300! It also boasted the 2nd largest display, at that time, without going to one of those Nook sized monstrocities. I looked for one for a few weeks before finally finding one. No one had them, not even Verizon stores. HHGregg was the ONLY store in my area to get them....Best Buy never did...and I was told never would.