To be perfectly honest if you really want to play the meta game going full str or full vit is just going to have wasted points on one end or another as you also have to consider gear and materia stat cap as opposed to the str plateaus for damage reduction in regards to parry and block as well as the contribution you will have from determination and crit rate. Vit is the easy way to go for sure as it no longer effects defense and is straight health. Go Vit and make str adjustments with gear is going to be signifcantly easier then keeping the running total and balancing as well as to make decisions on using dps accessories to contribute to overall.

@Maverick9123 I understand the sentiment but it is a hard thing to test and construct an accurate equation around as the monster has stats as well. But here is a link that at least made some ground but it is not the end all as parry does this dex does this. Hope it helps http://valk.dancing-mad.com/?page_id=227