I am currently using MK5, but MG2 also worked really well for me. So did Sprint's most recent one MK3, which came out as part of their official 4.3 stock update. I do get really good service at home, usually full bars, and at work not so much so, but still 2-3 bars consistently. Haven't noticed any real difference between the various modems I've tried, but also lucky enough (in my opinion obviously!) to not be living in an urban jungle, with lots of tall buildings and obstacles to cell service. My advice mainly is to just try several of them for long enough to see if you have one win out over the other, what works for me in Colorado is going to be different for you in your part of the country.