Personally, I think foil looks incredible. I've never seen a metallic paint solution that appealed to me. I was inclined to buy separate foil and adhesive but ended up going with some gold BMF for my first attempt. I figure it's probably better to minimize the variables when I'm learning new techniques.
Also, if I'm not mistaken, decal adherence over time shouldn't even really be a consideration. Since the foil should be sprayed over with a top coat to prevent tarnish as well as protect the surfaces, any decals would be as permanent as with any other finish, yes?
I tell you, I've been building and crafting my own whatever's for the past twenty years but when I decided to try my hand at modelling again... It's a whole new world compared to my teenage experiences in the early nineties. I only ever had testors enamels, testors cement, some crap putty, and sandpaper squares. Now, in addition to my subject research, it's taken me a week just to figure out which type of paint to go with, then another to figure out which airbrush to choose.
I'm sure you've all heard it before but... Damn.