My longest is something like 48 hours, but that was an insanely complicated piece.  I've found Vue 7 takes SOOOOOO much longer that Vue 6, though - I'm doing a comparison render - exactly the same image (though with a couple of tweaks - I'm using the new Vue 7 clouds and dynamic population for the eco-system).  The Vue 6 (infinite) took 7 mins to render at 640x480, set to final.  Same settings for the vue 7 render, but so for it's 40% done and has been going for about 4 HOURS.

Anyone got any idea how to reduce the render times for Vue 7?  Having both 6+7 installed on the same computer might not be helping, though....