Hi, I'm a european crested tit, and a very small punk rocker!
I find that they play quite well. I integrated Bases and Battleships into my colony wars set without any problems. However, I did sleeve my deck, so I don't know you can really tell the (alleged) difference in ink quality between sets.
I'm pretty sure David was asking about the power level of the cards and not the ink quality
But yes, you can tell which card comes from which set just by looking at their back through transparent sleeves.