I have had my Silhouette for almost a year and I am in love with it. I have gone through 3 mats since I bought it...they last forever! And I cut a ton with it. As for the mat moving, I was having that problem then realized I was loading it wrong...now I rarely have issues with the mat.
I am on my second blade with the machine....its probably getting close to the end, but I have been using my machine like crazy these past few weeks.
I absolutely love the intricacy of the cuts and the fact that I know exactly what size something is going to be before I cut it...makes it nice when I need to stamp something on it or when I am using a ton of cuts because I can then layer everything together on my computer to see how it will lay out before I cut it. There are also some great Silhouette Tutorial classes out there and they are worth every penny to learn new stuff about your machine. Hope this all helps!