The Banshee is reasonably tough, has large shield arms, and can mount impressive firepower. The lack (or near lack in the case of the S) of arm hard-points is a weakness in close quarters, and like most big assaults, they are rather slow (though not as slow as an Atlas.)
The E variant is obviously the most "meta" for it's ability to mount a pile of ballistics and energy weapons in various useful mixes. I've done very well with my Banshee E.
The S variant is a lot like an Atlas. Really, if you already have an Atlas, there's not much point to this mech, or, to turn it around, if you buy a Banshee S and like the other Banshees, you can probably skip the Atlas. It can pack an AC20, a pile of energy weapons, and 1 missile slot, be it an SRM or a big LRM. Overall, a good, flexible assault mech.
The M variant is, on an absolute scale, a total mess. Maybe if it had the same quirks as the Awesome's regarding heat and energy weapons, it would be tolerable. You can make some funny builds with it, such as the "super-Hunchback," but still... it tends to overheat and suffers a terrible lack of weapon variant for no real gains. Realistically, you can put almost as many energy weapons as you'd ever want on the other Banshees, so losing ballistics and missiles for more energy isn't a good deal. If this mech had a bunch of arm hardpoints, it would be the best Banshee vs. lights, but sadly, it even lacks that.
So, long story short: Banshee is a good mech, the E and S are quite good, and - for most people - the M is a grind that you sell when done.
Edited by oldradagast, 12 September 2014 - 01:54 PM.