First I'll compare the laser vomit ones.
SNV-1
All the weapons are in the arms
MAD-IIC
The real difference here is the Jumpjet and the extra couple DHS vs the difference in speed.
Honorable mention:
SNV-3
Able to Zombie with its Standard Engine.
SNV-C
Can't carry as many DHS but you can fit in an extra JJ.
Now lets compare the ATM boats
SNV-A
Low engine cap means I can pack a lot more ammo and max out an ATM alpha without Ghost heat.
You
can fit 4xATM12 but you have to chain fire them and I personally just accept a lower damage ATM setup if I can bring serious laser backup damage.
MAD-IIC-B
No ghost heat on anything. Faster. No JJs
The MAD IIC one that can take ballistics
MAD-IIC-A
The slow version.
MAD-IIC-A
The much faster version, didn't change the ratio of ammo though.
The difference is 5 damage per tap between a UAC10 and UAC5, I personally take the one that can fit the XL engine because speed is very nice in this nascar centric game.
The snipers
SNV-C
Fire 2 at a time .5 seconds after each other, the 4 in the torso are relatively high for peaking.
MAD-IIC-D
ECM isn't as huge a benefit as it used to be but this is a fun sniper mech.
I like the MAD IIC a lot, 68.5 KPH is very nice when you're moving in to vomit lasers. The Zombie SNV is pretty great though and having JJs is really nice as well.
A few of the SNV, not all of them, but a few get 10 CT 10 LT 10 RT structure, which every little bit helps and can be increased with the survival tree.
So some SNV variants can tank a little better than others.