my one VP game experience was Epotara - 17 players vying for 5 VPs. i thought that game worked fairly well. it was pretty challenging to get 5 capitals - once someone got within 2 everyone was on alert and it was only through some tricky diplomacy (to put it generously) that someone managed to grab the last 1.
the game did get into a bit of a quiet lull for awhile so i don't know if the same ratio would make sense, e.g. using ~ 1/3 of the # players as the target amount of VPs. that sounds a bit high to me - i think the game might be more interesting and exciting with a slightly lower total.
of course this is based on a data set of one...
