I'm familiar with using XHTML Mobile doctype for making mobile-only sites.

I am working on a site that currently relies heavily on tables and I am rewriting the markup. I was planning on using HTML 4.01 Transitional, but it's not currently a mobile-friendly site and I'd like to make it so. It will, however, primarily be for desktop/laptop users.

I'd like to know if there is any advantage to use a normal XHTML doctype (strict or transitional) if I plan on incorporating a mobile stylesheet later on.