LG VX-4700 / VX-4650 / AX-4750 / UX-4750

info needed: I've loved my LG 4500, but many near- dead spots despite nearby towers ("facing the wrong way" verizon tells me). Is the LG 4650 or the 8100 any more sensitive ? Some vzn staff say try the Moto.E815, but it's missing some of my favorite features that the LG's have. They also tell me analog isn't going to help in Charlotte N.C. area, just need slightly more sensitive reception. Not needing a camera, vcr, etc. Any comparisons appreciated. Thanks.