Ah so it should be 5 tons instead of the clan's 4?
Of the top of my head, yes. The range and/or damage are probably nerfed too but it's been a while since I looked at the CBT weapons tables. The heat might be more efficient per point of damage though, as that's often the case gaining range and damage but increasing heat massively, like the 50% increase between the old IS PPC and the new IS ERPPC for the same damage but extended range.
I'm not really a fan of IS built ER energy weapons though, the massive increase in heat means that you can shoot a 100m or so more, but overall your limiting your efficiency and ability to maintain fire. Clan ER weapons are a different story though.