The extra time only makes sense if you don't expect to die. Events like Dynamis or CoP/ZM Missions where wipes are expected don't benefit from the extra time.
But for pure XP party situations, yes, the lower cost/time makes the +1 superior.
This migh sound silly but its the +1 that means that it lasts longer than the normal one. Two times as long in fact. so if the normal one is going for like 10-14k and this is going for 20k dosent take much to figure out that this is a better buy for your gil.
that and you get better stats too...
but if you would rather buy the normal one...
