The 3S is the only Banshee i've had a chance to try out...
First two matches I really struggled. It's hard to actually use the weight on a 95 ton mech with the weapon slots all bundled together and a pretty small max engine size. At first I tried to boat medium lasers and an AC20 as the ultimate infighter, but I simply couldnt make the numbers work. I tried an odd mix of AC20, MLs and a PPC. It sucked and I was disparaging the mech as a really bad purchase.
Then I settled on my final config.
STD320, DHS, ES, 3xLL, AC20, Max armour
This think is an absolute beast. Considering i've only piloted it and my trust Yang since stats were reset (100% PUG), and my first two matches went pretty horribly... the stats speak for themselves:
I havent actually died once since! It's been a pretty stunning run. If you are wondering about the 6+2=9 thing... you can tie. And when you tie, everyone gets 0 base XP and Cbills, really lame PGI.
There are a few downsides. Your turn rate in an assault with a 320 can be a bit on the glacial side, so pesky spiders are, well, pesky. Most importantly, all of your weapons are torso mounted, so you can get into a lot of situations where you simply cant target the enemy. The vertical degree of movement seems very limited.
Now the plus sides... here is the biggest one. This thing is a #$@#$@#ing zombie. Both arms as shields, a crap ton of armour and nice hitboxes coupled with a standard engine makes this by far the most durable mech in the game. It astounds me how incredibly durable this thing actually is. I have had matches where I got into face humping contests with 100% healthy Atlases, basically just traded shot for shot. Result... 1 dead Atlas and me walking away at 80% health.
It is simply stunning how durable this ******* is.
I will warn though, the options with the 3S are incredibly limited. You will struggle to just use the weight available due to hardpoint locations. I highly suggest you try out a 3xLL + AC20 build though, its really works well for me.