Having a complete nightmare with Sophos clients controlled with Enterprise Console at the moment.... nearly 2500+ machines and another 1600 to come onboard soon.
Niggly performance issues on about 10% of the clients that we're liaising with Sophos support about. I think it's a duff build from a poor outside contractor that's caused the problem.
All said though, I'd get Sophos again and again and.... well, you get the idea.
The reseller we've just used for renewal (another 3 years) was great, we've got a direct line into their support team for above mentioned niggles at the mo, plus excellent support for bringing the other 1600+ into the fold using a roaming Enterprise Console running on a VM that's being carted around on a laptop. Also helped them root out a nasty bug in 9.5.x client that'll sting a good number of people.
The only thing I'd say that because of the diversity of our environment, is that the HIPS function needs a fair bit of TLC ongoing, but that's part of the fun to be honest!
Server-wise, we've about 250 servers currently, with another 150+ to be brought into the fold as with the additional workstations. To get all of this working with upwards of 200 sites has taken some pretty hairy work with HTTP and SMB repositories and through of this, their support has been first class.
Sophos is a slam-dunk really.
just my ten pence though!