Cream soda can work very well with vodka, but only if you get the amounts just right. I don't know the exact mixture needed, I usually go by the mix 'n sip method.
One thing that does not go well is pixy stix. Bolstered by my successful addition of cream soda (one of my favorite beverages, which I thought never got the popularity it deserved), I wanted to add another secret passion of mine in order to make a super drink. This sensation would taste great while still geting you totally smashed, I planned on calling the drink "the 'thrax". Unfourtunatly it was a horrible tasting mess that ended up wasting a bag of pixy stix, a liter of cream soda, and lots of vodka.
Never again will I try to fly too close to the sun