Phd synergy ISO 7 vs phd diet whey?

I was just wondering if any one has any advice on which protein would be more beneficial to me. I have been taking phd diet whey for the past 6 months while doing insanity and have managed to shed the excess fat/weight I was hoping to. Now I'm at the stage where I am doing insanity and heavy lifting on alternate days for three day cycles with a day off Inbetween in the hope to tone up further/gain more muscle mass.

I've heard good things about synergy ISO 7 for muscle gain but would it be a waste of money considering I'm still doing three high intensity cardio sessions during the week, would this be counter productive? I don't really have a problem putting weight back on if needed as long as it's muscle as I'm not entirely set on sticking to my current weight.

I guess what I'm asking is am I better sticking to phd diet like I have been or taking a shot on something new, or even using both? Diet whey on cardio days and synergy on lifting days?

My stats are -

31 yr old
5,10
160 lbs
12% BF

Thanks