Hi from Osaka (here through 1/12),
The tutorial in your link is well written but it requires that you write code which increases the IT maintenance cost of your solution (since you have to have a developer to compile and maintain that code). In general, ShP workflows have some advantages in 2010 (editable in Visio, copyable across sites, etc.) but by and large the ShP Designer workflows aren't powerful enough to do a lot. You'll end up having to write code anyway and that's expensive for most companies.
We prefer to do codeless workflows in InfoPath not only because they are cheaper long-term but because a) have better usability (status easily displayed in the form where users want to see it), b) are easy to setup without code (add rules and actions to your form using InfoPath Designer), c) can be used without SharePoint, and d) can be easily customized down the road and they live in the form so they can migrate to other locations. The big limitation with InfoPath forms-based workflows are that they require more planning and design to implement complex workflows (define your workflow state diagram, actions and user roles). However, even SharePoint workflows are not simple to design in SPD and they require planning/design (but it's nice to see the Visio support in 2010). Most complex workflows end up moving to custom WWF (code) or Nintex or some other platform since ShP workflow doesn't handle complex workflows well.
Also, SharePoint doesn't control access to forms dynamically based on workflow state. To do that requires more work to move forms from one library to another. InfoPath can be setup to check user assignment and roles on open and switch views to prevent editing and hide data to the user but this isn't totally secure since users could still save the XML on open and open/edit in notepad and upload to ShP. In practice, though, unless you have a sensitive process, the InfoPath forms-based workflow are a good place to start because they can be done relatively simply without a ton of investment. Define your states, actoins, user roles and change the form to provide the logic and conditional hide/show to handle them.
To setup a prototype workflow in InfoPath will require some setup and configuration. We have an introductory training lab on creating a simple workflow. I'll ask someone to post a link.
If you are just beginning, I recommend that you purchase a couple hours of paid support and have one of our experts walk you through some examples. That will be well worth the time investment up front and you'll learn a lot that will prevent mistakes down the road.
More soon,