I have had the accuquilt go since 2012 and have had no problems with it. The mats do wear out but it takes a hundreds of cuts before they do. They are relatively inexpensive to replace. My dies are still as sharp as when they were new. I mainly use my cutter to cut the shapes that are hard to do by hand and impossible by rotary cutter: circles, stars, hexagons, hearts, feathers,flowers, stems,etc.
I have had only one issue with a die I bought last year.....the "2 1/2 multiples" it cuts 9 2 1/2 inch squares at once and is perfect for cutting scraps into 2 1/2 squares. The die when it was new had several places that just didn't cut all the way through. Returned it to the dealer and she replaced it with a new one that cuts perfectly. I think it was just a manufacturing defect.