I finally found this site after going into the Sprint store on Howe in Arden/Arcade for an unrelated problem and the guy there told me worst case scenario, we'll all have LTE in the market by the end of the year, but he said he is guessing within 30-45 days. So, I had to do some research because I don't always trust what the guys at the store say.
That being said, I live out in Rancho Cordova and my service SUCKS overall. I had to get an Airvana four years ago just to keep calls up in my house. I've been watching data capacity upgrades and everything on the Sprint site for the past six months, but nothing has changed. I frequent the 50 corridor between Rancho city hall and midtown for work. I'm going to try to contribute to mapping on Sensorly while I'm driving around, especially around Rancho city hall because I live within spitting distance from there. I'm more interested in improvements in the midtown and downtown area because my DL/UL speed sitting at my desk is 40kbps/140 kbps. Only one test, but pathetic to say the least.
Anyway, I'll try to help with the mapping progress and will try to post what I have found as I can. About to go move my car and I will run a map and see what I come up with in midtown.