I personally love LMGs, but most people hate them once they use them. They're a phony pony to carry, you go through tons of BBs (making them expensive), you instantly become a target every time you fire, they can be particularly finicky, and overall they bring a lot of annoyances to the table. Assault rifles are easier to play with and allow a far wider style of play. Their only advantage is they allow a lot of fire for an extended period, but it's not like it's an instant death machine for all who face it. Really, you limit yourself usually to not getting many kills, instead being in a support role of suppression.
Basically, I'm telling you to really think of lugging around an LMG around all day. Go with the Masada for now. Then, maybe later, go for an LMG.