Hi Ener,
A lot of it would depend on the amount of scripts and physics being used and on whether people already have the sim's assets cached in their viewer. A sim with 80 avatars wearing many scripted items constantly moving around would behave very differently from one where avatars don't wear a lot of scripts and stand in place most of the time. Avatars that need to download assets for 60,000 prims will see more viewer lag than ones who've already rezzed them. Your mileage will therefore vary depending on how much stress you put on the sim and whether you've already visited it in the past.