I think the Catapult has its good and bad points.
Small side torso's make it safer to use an XL engine because the side torso's are rarely destroyed. On the other hand the Catapult also has a huge head hitbox making it easier to kill then most other mechs.
As for the torso twist...well i couldn't care less if it was reduced. I've never understood why a long-range support mech would need such a good torso twist anyway.
Now, the variants:
A1 (and other missile variants) - I've never had much of a problem with this mech. It may do high damage (maybe slightly too high) but that damage is spread, so it's not like it's a great killing mech.
If anything, i'd prefer that LRM's were made competitive again so we might occasionally see this mech performing the intended role. I tried an SRM A1 while working up the XP for my K2 but just didn't like using a brawler mech.
K2 - I have a love/hate relationship with this mech. I used a K2 (PPC's) through CB and still have it (ERPPC's) now, but it's just not a competitive mech imo....until you make ballistics the main weapons instead of energy (not including the LL versions)...and partially because of the huge head hitbox. But i refuse to play one of those ballistic abominations
Actually, it just occurred to me that the torso twist probably is the thing that makes AC20 K2's so good. I was in a match yesterday, in my K2 (ERPPC's) and after the "sniping" phase turned into the brawling range fights i managed to get behind an enemy Atlas and no matter how much he turned and twisted he couldn't get me from behind him and i killed him.
Then i ran straight into an AC20 K2.
No point in trying to get away as he would have just blown me up as i ran away, so i got behind him, but by barely moving his legs and swinging his torso right around he managed to keep me in front of him the whole time and destroyed me in a couple of ct hits.