I have been fiddling about with my new vforum for a few days as we are thinking of moving our 100 + members over from our present Hyperboards home. I have to say that the support one receives on here is second to none, much better than others we have used in the last seven years. The forums themselves are very admin friendly, and I cant think of one thing that seriously needs changing.
As for the ad free prices, I think that perhaps there should be a set monthly rate option, as our forum receives on average nearly 4000 page hits a day, and is going to cost me a lot more than I pay Hyperboards.
I pay Hyperboards $4 which is about £2 per month for ad free but vforums will cost me about £12 per month.