We are using Windows Deployment Services with server running in legacy mode. So RIS, yep.
See also this WAIK User's guide.
But the small problem with the deployment for us is the troubles with configuration management. Our network is very heterogeneous. I can't recall the moment we weren't in transition. New people come, we purchase new hardware that already uses new kind of software. But we also need to keep all these old stuff working because it's all in business. Surely it creates specific problems. Mostly because I need to keep out network in a state that is certified by internal rules. The organization wants users to have their desktops look standard to not confuse the basic operations, to avoid all these questions about "how do I write my document? I need to send it to my collegues right know". So basically we create a standard masted image of OS with several general applications such as Office preinstalled. At the same time different hardware requires different software, unfortunately. This all requires keeping several images on the server and that's surely not a handy thing.
As for the topic what we do afer deploying the OS onto computers, we deploy applications. We are using group policies to deploy MSI packages throught the departments. I would say it's not that easy as it seems from the wording when you first start thinking about deployment. The most complex moment is again connected to the distribution of the software across the domain. While we deploy the standard images onto equal hardware, the problem here is to supply departments with different software specific for the tasks people do there. That involves the need to script the distribution. I can't said that it was always possible to me to automate deploying speicific configurations for all cases. Sometimes I am unable to automate the configurations because such complex scritping is out of my scope and it takes to much to build it. I would prefer the way to configure the OS image after deploying it to users. I heard somewhere Scriptlogic offers something similar but I haven't any opportunity to work with it yet. If anyone of you have worked with it I will be interested in hearing from you.
To the point, does some of you have any experience in implementing such operations? What's best practice for you?
By the way, there's a good article explaining what's new in WDS against the basic RIS you might want to read.