Big Bang is Indica dominate and very hardy. If you like strains like White Rhino, White Widow, etc you'll love Big Bang.
I haven't grown a purple strain yet, but from what I've bought and tasted, the purples tend to have the worst flavor and just so so potency. Add to the fact that you usually need to grow a lot and get the right pheno, or get your temps really low to bring out the color, I just don't think they're worth it.
When it comes to bag appeal, I'd prefer to see dark dense nugs with lots of orange hairs all over. Purple just doesn't excite me anymore now that I know what causes it.