70% of what I use is Vallejo. 20% Foundry and then 10% Citadel 

Indeed. Almost all my painting is Vallejo (as well as priming, varnishing, water effects and pumice basing paste). They are also highly recommended by 'El Mercenario', although he does rate the Citadel metallics as better.

The one issue is that some of the Vallejo range develop colour separation if left standing unused. Thorough mixing is important but I often leave these bottles upside down in order to make the mixing process easier.

Robert

It is important to shake their paints very well.  I actually tried to return the first one I ever bought to the store becuse it seemed to be just powder and ooze.  The employee showed me what to do...shake it and then roll it, repeating several times.  Some times you have to sqeaze the bottom to break up the sediment before shaking.  It's funny that the color I first bought was german feldgrau, at least 10 years ago.  I'm still using that same bottle and have several german armies done (6mm, 15mm and 28's).

Another key is getting the paint thinned just right.  I stopped globbing the paint on a few years ago and started doing multiple thin coats.  Their paints are so good that you can brush paint even 28mm tanks and it's no problem.