At my last job (school district) we used FOG. Our environment was entirely Windows XP with about 2,000 systems. I tried the whole sysprep thing, but I found it to be quite unpredictable, so I stopped trusting it. I ended up favoring just setting up one image per system build, which worked out okay in my case because we bought systems in massive flocks, so I only had a few images around even though we had 2,000 systems.
My boss at the time was hesitant to trust Linux so he sent me to a Microsoft conference to see a demo on whatever imaging functions Server 2008 contained, since some people at the time were raving about how nice it is to have integrated imaging to your server. Ironically, it crashed during the presentation, so FOG ran the show and still does even though I've been out of there for a year or two. FOG is Linux based, free, open source, aka awesome. It works predictably well and requires minimal terminal work to get rolling. It's become quite the standard when it comes to school districts since it's a low cost way to get a massive amount of systems imaged - my current district I'm working for uses it as well as the next neighboring district to our north.
I'd be giving that a shot to see if it works for your particular environment before I'd invest money into proprietary solutions.