I think there’s no right and wrong on how you approach this matter, as long as the benefits you gain out of it can be considered a worthwhile investment, irregardless whether it’s financial, experience, knowledge and even market exposure.

Site’s usability level has always been closely associated with most common used and implemented design methods. Once users are well accustomed to a certain specific standard, changing it simply means creating confusion and goes against a set of common user expectations, hence reduces how “friendly” a site would be.