I've only just noticed this post or I would have commented sooner.
I do use buttercream but only as fillings for cakes or as toppings for cupcakes which I only really do for friends and family. Contrary to belief, I don't actually make that many fruit cakes either.
My most popular cake for past clients is chocolate. It was only last year that I had to make the decision whether to cease making cakes altogether (although I do still make them for clients who have been coming to me since the beginning if I can fit them in). My sugar art has kind of taken over and I am more than happy about that. With my Online Tutorials being so popular they have made me a well known name in the sugar world which brings me opportunities to teach here, there and everywhere. I am at this very minute in Seattle and will hopefully be making time to visit the Cake Central crew very soon!
The best recipes for buttercream in my opinion are on this very site. My personal favourite is Italian Meringue! I'm no expert in the making of buttercream but I make an excellent taster! I hope that clarifies a few things for you.