For the basic coats I used GW Foundation Tausept Ochre and Folkart Yellow Ochre - quite different in level of pigment, and it took two coats of Folkart where I only needed a single coat of GW over black primer. Probably not a fair comparison since that's the whole point of the foundation paints... so let me ignore that one.
The other colours were a fairer comparison. My biggest complaint is the texture of the craft paints. The actual pigment levels were very similar between the two types of paint directly from the pot/tube, but the consistency of the craft paints was rather glutinous. In some of the colours, it was as though the manufacturer had sneezed repeatedly into the mix; the consistency was almost like white (PVA) glue.
What this meant was that I needed much more thinning to make the hobby paints workable, which obviously reduced the opacity and then led to my needing two coats of most colours to get an even coverage (honourable mention for gray here).
Overall, I have seen enough to prove to myself that hobby paints are better than craft paints for the way that I paint. Craft paints may work for you, and the end results are decent enough, but I will go back to hobby paints from now on.
Oh - and if you're wondering, the upper picture is craft paints and the lower picture is my usual hobby paints...