I think the refire rate is great, but I still feel it is quite weak.
You have to hit consistently in order to do any real damage.
It is difficult to hit Light Mechs consistently over a period of time because they can dodge pretty easily and you have to lead.
I have to ask, how is this a change? You still needed to hit targets consistently with the old ACs.
Hell, you needed to hit them more consistently, because each shot was more valuable. The old UACs wasted ammo because often all the shots of the burst didn't hit.
Besides, if you do more than circle strafe in a fight, you'll get a point where your target is moving rather slowly relatively to you, and then you pound them, doing far more damage than the old autocannons could muster before starting up again.
If you compare the standard AC10 to a large laser and then the UAC10 as outclassing both of those, the comparison comes out rather even given their strengths and weaknesses.