According to other posts on this forum, the formula for the relationship between constitution and vitality is:
HP = (Level + 1)/2) x (0,0088 x CON^3 + 0,1772 x CON^2 + 6,8279 x CON + 13,08)
(credit to Jasper1983)
http://www.larian.com/forums/ubbthreads.php?ubb=showflat&Number=532817I've plugged this formula into a spreadsheet and under no circumstances does Picture of Health confer more HP than the 2 points in Constitution that can be obtained by trading an unused talent point to the demon. With the added bonus to Action Points that you get from Constitution, there is no reason to take Picture of Health as a talent unless you have constitution maxed and want even more HP (but that stat allocation makes for a rather useless meat shield character). It seems to me that taking +2 Constitution is the clear winner.
Any thoughts? Am I missing something?