It is no longer, “Do I need to update my website for mobile devices?” Rather “How can I make my site mobile ready ASAP?”.
With over 8 websites of my own on the server, using wordpress responsive themes takes about 2 hours to replace the theme and modify
Does it always take 2 hours? Not always… It really depends on the number of pages and how elaborate the original layout.
Also, this is for sites that already have wordpress as the installed platform of the original site.