Both single stage and Bccc are great paints if you are using quality products like PPG, DuPont. base coat clear is probably the most forgiving to the do it your self guy as it acts and sprays much like the old lacquers that many of you are used to, and it's quick dry times allows you to make small corrections and the ability to nub sand dirt or debris before the final clear coat. In my opinion it takes a more experienced painter to yield great results with single stage. Most of the painters that learned to spray laquer then the single stage paints that became standard in the eighties can usually spray the newer base coat clears and water base paints like a Boss, but I see the newer generation of painters struggle to lay down a good single stage job out of the gun.
My thoughts are, if you are going to do it yourself do what you feel comfortable with. And if your the kinda guy that is taking his car to someone else and insists on using single stage and the painter is only used to spraying Bccc, get ready for many hours of cutting and buffing.
Here's some advice for people who want a really good paint job on a budget and don't want to tackle painting their car theirselves. Do al your body work yourself or have it done by someone reputable then buy good paint products from PPG or Dupont then take your car to the nearest econo paint or maco or whatever shop near you that does super cheap volume paint jobs and see if they will paint your car with your supplied materials. I have found that their is some pretty talented painters do the sheer volume of cars they paint in a week. I know one guy that sprays as many as 45 cars a week!