Have been in talks with them for an Australian uni (it's not very widely used here, but one of the major music festivals here is rolling it out in Feb), but haven't made a decision yet.
I'd like to use it, however for the money it costs (we were quoted about $5-6k/annum) I don't think we will get that much student engagement, and my marketing team isn't responsible for current student experience, only prospective recruiting. It would be best used for our Open Day, but for $6k to come out of our budget just for that purpose, I don't think it's worth it.
I have read what I could online and SCVNGR has given me a reference to contact but I thought that with hundreds of higher ed clients listed:http://www.scvngr.com/clients
I would get more feedback. It seems that college life/student life office might be using it more than the web folks?