How to Get the Best LTE Reception with a Sprint iPhone 5?

I have an iPhone 5 with Sprint and the service sucks. However, I seem to get the best signal with LTE whenever that shows up in the top left corner. My Wi-Fi service with sprint sucks. It never works. But something about this LTE, everything works properly. How I can assure to receive the best service with the LTE and KEEP IT?

I didn't think Sprint's LTE was even available yet. All the articles say you're stuck with 3G speed till they get it going.