Thought I'd post here since if you're using web services you might also be a PowerShell wonk like me.
I've created a Moodle module that uses the web services. We've been using it in production for the better part of this year with no issues. We use it to provision new users and enrol them in courses.
The module is open source and I'm happy to take suggestions (or pull requests) if there's functionality you need! You can find it on GitHub here: https://github.com/WodongaTAFE/PSMoodle and install it from the PowerShell Gallery using Install-Module.