We went there in Jan 2008. It was because, first, we heard that it was a beginner friendly ski resort. Second, we got a good deal to stay 3 nights at the lovely hotel Montana, including simple breakfast, lunch packs, 3-courses fine dinner, and all transfer between both the train station and ski site and the hotel! What can you ask more?
It took around 2.5 hours by train from Zurich to Disentis. We spent a sunny vacation there. The snow was perfect. I stayed around a couple of learner slopes, while my hubby sometimes went all the way up and enjoyed some wild skiing. As an inexperienced skier, I enjoyed my time in Disentis more than in Laax, where we were last winter. It was less crowded (both on the runs and in the restaurants). The runs were broad. And the staff extremely friendly and helpful.
We also visited a spa in Sedrun, as usual we like ski with spa. A 15-minute ride from train station Alca da Fontauna followed by a 5-10 minute walk brought us to the spa. It was a small one, but fair with the price.