Well, there are ways to balance everything like the criminally short range of IS pulse lasers and the enormous proportional mass increases for Clan models (although Clan tech is a little broken by design), and if need be you can change the damage, range, hit modifiers, or heat further, and if you still feel it needs tweaking you can change the size and mass while we are practically reinventing the weapon. Finally, there is BV as a balancing factor so no matter how broken it is in construction it can still be brought into check in a BV balanced game through price.
Also, the cluster tables have been expanded for weapons like the MML 3, 7, and 9 so the tables are not an issue.