There are no set routes for DME. They can change from day to day. But, usually there will be 3 resorts per run...sometimes 4 (I know that YC, BC, BW, and POR have been lumped together, but three of them are next door to each other).
As for rating DME, the vast majority of guests find DME to work very well for them. I have seen very few reports that are negative and most of those reports had some kind of logical reasons for the negative issues.