4G LTE through Verizon & Xbox Live.?

Recently, my dad bought one of the 4G LTE Modems from Verizon wireless, because we were getting sick and tired of crappy dial-up(yes it's around). I haven't played Live on the connection mainly because I'm not sure if it would be fast enough to allow me to play online, and two because we only have a 10gig a month limit. This is really a two part question. 1) Would the speeds be adequate enough so that I wouldn'y lag out all the time? 2) Roughly how much memory is used when playing online?