There are 10 new mechs to get your pilot hands on in MW4: Mercenaries and there should be some new death machine that will be a new favorite for experienced mech pilots. While some pilots will likely gravitate to the big mechs like the new Fafnir. I personally care for the small and nimble mechs such as the new Puma which packs enough firepower to bring down even the big boys yet fast enough to avoid catching some lasers and missiles