Mercenary is great when the combat is varied. Razor is great during a standoff. Cyclone is great for run n' gunning. Any of the shotguns are great for LA also. Don't believe the TR hype, the GD-7F is not a great weapon, TR just has a fixation with stats pages and not actual gameplay.
there is almost no reason to use default over the select fire variant, 23 rpm is negligible where SPA is a boon, especially on a platform that has enough velocity to take the hit to that area while still needing minimal leading outside of long to super long range. GCS, comp, SPA, UBGL, 1x or 2x sight. you have a very quick 4 tap to the dome for killing unaware snipers or others sitting still behind cover or on a turret, the grenade launcher lets you, with a little bit of cover for reloads, take on maxes without wasting your C4, and the comp lets you go full auto out pretty far before needing to burst for reliable effects on target. in towers I may pull out the Cyclone, but for most needs, the GCS is where it's at
SMGs are the best if you want to have any ability to fight back while airborne and I would suggest the Blitz because the COF multiplier will have you spitting bullets everywhere. Shotguns are overrated in my opinion and are really only useful in the perfect conditions (i.e., a small space and relatively low population). I have to say that my current favorite, hands down, has to be the Razor and I kick myself for not unlocking it first. It does really well with a hybrid "close/long" setup like laser+compensator+HVA but you can still get away with laser+nothing or even laser+flash suppressor+HVA up to a decent range. When desired, you can also spec the Razor for good mid-long range sharpshooting with foregrip+compensator+HVA or something along those lines because the projectile velocity is relatively high and it is far more controllable than the ACX-11 and wins against the ACX-11 hands down thanks to 10+ ammo, much higher projectile velocity and less vertical recoil- only area where ACX-11 > Razor is the horizontal recoil department but a foregrip pretty much nullifies that.
I always wondered what the point of the advanced foregrip on ACX-11 when there is practically no horizontal recoil
