You should be able to download/install the demo Sonar current version, and bring in each wrk file and create midi output files, as well as evaluate the product, and uninstall it if you don't decide Sonar is for you.
I would also suggest to you that Sonar has become unbelievably more feature rich and solid than whatever it looked like 10 years ago, and you might just like its new look and functionality.
Please note that the demo version (to the best of my awareness) does not come with a lot of the plugins you would usually get with the full product, but the demo version is really to test Sonar itself - just didn't want you to be frustrated by that. :)
Anyways, I think you should be able to do what you intend to do with your wrk/midi conversion just fine with the demo, unless I am missing something.
Bob Bone