The only IS laser I really want changes to is the pulse lasers. 400m LPL is awful taking in to account of the heat generated, damage done, alternative weapons available and the fact it is mounted on a 54km/h assault with paper armour adds to the insult.
The CLPL on the other hand is very capable, I love using the Novacat with MASC along with it. It have reasonable armour and moves nearly 2 times faster than the Awesome with MASC, while the weapons have higher damage and far longer range.