I see the metagame broken down a few different ways.
Exactly what it sounds like. There is no such thing as enough dakka. Cosmic Era suits, Heavyarms, etc.
Straight builds, essentially. No fancy-schmancy customization. Whether its a Zaku or if its the Turn A, its built to specs. Polished of course, not just snap-assembled, but built to specs.
These guys don't care about glorious battles. They just want to win. Therefore, they're going to do their best to blow it all up before you have a chance. Moonlight Butterflies, Wing Zero's buster rifle of doom, anything that could potentially demolish everything up to and including the battlefield itself.
This one would probably be very popular. Different from beam spam in regards to the fact that this is usually one enormous attack that wipes it all out, as opposed to the bajillion beams/missiles/dakka.
Abusing dem plavsky hax to achieve ridiculous things. See GBF/GBFT for examples of this. Includes extremely heavy gunpla customization to create unique takes/designs on Gundams with wildly varying abilities. Mixes very easily with FTK/OTK playstyles. Expect the most OP stuff to come from OTK Haxxors, with lots of "get gud scrub" comments to come from this group.
The guys who just want to have a good time (not that this excludes other groups like Beam Spam or Haxxors) and like melee combat. Epyons, Tallgeese, Hyaku Shikis, Mobile Fighters, etc. Can easily be merged with other groups so this would be more of a larger group with subset groups of Purists and Haxxors and stuff. Beam Spammers hate these guys if they manage to avoid the dakka and get up close.
Teams based around various factions in the Gundam universe. Use suits only from that faction. Principality of Zeon, OZ, Titans, etc.
Mobile Armors here. All day, every day. ONCE THE BIG ZAM GOES INTO MASS PRODUCTION, etc, etc.
Prefer ambushing the opponent. Expect to see lots of Deathscythes, Shadow Gundams, SDs (small so can hide better), setting up traps, sabotage, etc.
They fight only with the glory of the Ball.