Check also his other web page. Nice to see linux used by artist :).
…I found that Photoshop and the other proprietary software packages we had been using for years generally had more polished interfaces and more advanced features than the free software we chose. But the free software had more than enough of the core capabilities we needed in my classes, and also often featured desirable capabilities missing in the proprietary software.
The switch saved thousands of dollars in software upgrades. As a result I was able to dramatically lower the lab fee for each class, and require instead that the students purchase additional textbooks. These textbooks enriched the class experience, yet the overall cost to each student was significantly less, which they appreciated. …
Source : newsforge.com.