The question here is not necessarily about speeds but rather stability. I'd strongly suggest deciding on maximum number of users (5 at the most for a 100 mbps box). And fix a specific time when all you testers add high activity torrents and see how the box takes it.
And am sure that this will have ftp access to take stuff out? Please test that as well since that tends to give headaches to seedbox admins if not done properly
Thanks for the suggestions.Yes I have provided ftp access too. And as for the number of users I am going with 6 on this one.Lets see how the box fares.