The Kulas is still pretty good even without abusing the ETS. But yes, the fact that you have 21s burners that don't have to be pumped makes it so you can have 0 power on engines while burning(since burners can't recharge while being used anyway, only when being "pumped") and the AI will never do this.
Even without its burners the Kulas is like a slightly upgraded Perseus(and that's saying a lot considering how amazing the Perseus is). It has similar turn times with a slightly faster pitch and a slightly slower roll, similar durability(-70 hull, +60 shields), and more firepower. A single 4-bank can output 50% more DPS than a 2+2 configuration, which becomes important when you'll mostly be using the Balor.
And it makes sense for the Kulas to outperform FS2 craft while not being quite TEI level, it wasn't designed from scratch to be a military fighter, just refitted into one. It performs a similar niche to the Draco but in a lower-tech and lower-power fashion.