I'm not sure if you heard the news, but apparently the GSM moto g does not have band 12 lte. This directly and pretty seriously impacts T-Mobile coverage, since this frequency band provides much better coverage indoors and in crowded spaces. Motorola just pulled this compatibility from their site a few days ago. Here is their spec list now :
Moto G - GSM (XT1540)
LTE (2, 4, 5, 7, 17)
UMTS/HSPA+ (850, 1700/AWS, 1900, 2100 MHz)
GSM/GPRS/EDGE (850, 900, 1800, 1900 MHz)
This may or may not affect you depending where you are in the country, and can check their coverage at this linkhttp://www.spectrumgateway.com/_/rsrc/1439318929670/t-mobile-700a-spectrum/TMOvsChan51.jpg. Keep in mind that even if you aren't in this coverage area that T-Mobile is expected to massively increase the area of this coverage over the next year.