I use both Vallejo and GW. I prefer the dropper bottles, but on occassion they get clogged in teh nipple but a little pin takes care of that. I save the craft paint for terrain. If you can work magic with craft paint, then go for it; I find the mini-specific brands work better for me...
I generally have Vall for most paints, gw for metallics, and gw washes. My local store doesnt carry Vall so I have to sub GW sometimes but hasnt been an issue colorwise.
I think, like many things in life, you would best serve yourself trying some different ones and seeing for yourself. Such as I dont see GW yellow coating better than vallejo. I have had minor consistancy issues on occassion with both brands. I would still use them over craft paints though as I find them gloppy. But hey, at .50 why not try a few colors and see if they will suit your needs? Snag some grey and brown that can readily be used for terrain so you will surely use it anyways. If it works well, they even sell sample sets. If they work well get some more. If it's not for you they end up on the greystone castle for Vlad teh Impaler.
I know the vall and old GW colors so I will stick with them. The new range does fill some holes that vallejo had and gw didnt though.
Hope that helps...
J