Napkin notes on the new cloak:
The moon cycle of base line and cloak version sync up every 4 moon cycles (i.e. every 3min). Over that period you go from having 4x NM, 4xHM, 4xFM to 3xNM, 3xHM, 6xFM. That represents a damage increase on your moon spells of 17% and you've also generated 17% more Astral Power from your moons. That's 50 more ASP, so 1.25 more Starsurge or SotF Starfall.
So, if all the moon spells add up to about 5% of your damage, this would be a little less than a 1% damage increase before factoring in the small astral power gain.