Based on conversations with faculty at "top 50" schools, the applicant split for quant/CB is heavily skewed to CB, but schools are looking to make more of an effort to beef up their quant candidates because of the gradual shift towards quantitative analysis in the marketing space. I was informed by faculty at more than one school that the rate of acceptance for quant candidates is likely to be higher compared to that for CB candidates. Though, my hunch is that this could simply be a function of quant candidates having a tighter range of qualification (since it's a more scientific space, candidates need to be mathy/econ folk as opposed to CB where you get a wider range of undergraduate/graduate competencies in candidates).
Regardless, best of luck to you!