As it stands on live, non pet sorcs are underperforming. With the upcoming changes of 300 magicka return on daedric summoning abilities the gap becomes even bigger, giving pet sorc a major sustain boost of 750~ resource return every rotation(10 sec rotation static 1.5 curse 1 monkey use), leaving non pet sorc behind with 250~ per rotation (which is similar to what they had from the old rebate passive, using storm atronach ultimate).
I am happy that sorc sustain is getting better this patch (frags) because it has been an issue for quite a while, but the gap between pets & no pets is growing wider & wider.