Its not heavily used but it manages very well - no problems so far.
We are a vanilla network, almost 1000 PCs/Laptops, we heavily use Exchange/Home Drives and the system in general.
VLE: We use Frog, gives us all the VLE functions and it has Secure Gateway which allows any home Windows/Mac to connect to a classroom of PCs. We don't have the capacity for virtual machines (shame really because that would work too). Frog also allows any staff member to create online resources not just a file browser, don't have to be clued up with IT either.
Our LEA is EIS and they serve us well, new Lightspeed allows any BYOD to work with a domain username/password but we put the Wi-Fi code in for the users. I like the idea of giving it out but I think we need to tighten things up first.
We use SIMs (capita) and again this serves us well, we did use Bromcom a long time ago in a galaxy far far away and have not looked back since.
We also have Macs on our system which go through a Mac server which then connects up to our AD system, our technician spent the last 12/18 months getting it just perfect (after them ignoring us for years how they should do it). We are unable to get iPads working on the Mac server due to its OS, we would have to upgrade which will cost us.
Have about 90% Wireless covered, some areas could do with a better system though - age/speed not coping so well these days.
Not sure what else to add, but hopefully the above helps.