The problem is that using a third party managed system to many people here (myself included) just seems like a waste of money when you can easily do all the things that classlink or CC4 can do with AD group policy and a few select tools.
Take for example the school I'm in now. It bought into classlink XP at the cost of £25k before I took over. In order to upgrade the workstations to a new service pack you have to pay an annual fee to viglen of around £14k. Or you can not pay them, install an untarnished copy of xp (or 7, but not vista), and update it using the standard SP3 that M$ provide for download. The server has non of the classlink extras installed anymore, other than ghost, but is still easy to manage.
Managed systems like classlink and CC are just a way for big IT vendors to hold you to ransom every year. If you dont know how to manage group policy, then google is a friend. Or get an IT company in to do the initial setup and provide training to yourselves. The worst thing you can do is tie yourself into another dodgy contract.