Hi,
Had Xirrus here at Holy Trinity for around about 2 years now. Does exactly what it says on the tin really. Set it up and have barely had to touch it since. 24 points scattered about the school and we have no trouble with large numbers on the same AP. We run 2 SSIDs with one for teachers and school laptops, while the other is VLANed off for the students with their own laptops (and iPhones :-().
Install wise we ran the cables (and I'd even started configuring the array before the technician got here. New tech kit. Couldn't leave it alone.) and then we just had to put them up and turn them on. Before we'd even finished the deployment of the arrays we had teachers delighted with the new wireless. One was even in a different section and had picked up a new array from elsewhere.
Only time we ever see the kit down is when there's a power cut. I reckon it's the best investment we've made here in my short time.
Hope that's informative.
Chris Hughes
Network Manager, The Holy Trinity C of E Secondary School Crawley