We bought our M8540 which is essentially the same as an M9540 in June 2010 and have had no issues with it. We've never checked fuel usage, but it doesn't seem excessive based on our other tractors. We got the 12/12 with same size tires that come standard on the M9540. We got two rear remotes and wish we had gotten the third. We pull a 10'6" Woods DS1260 rotary cutter and use a 10' drag scraper and Land Pride HR3584 box scraper.
We have been very happy with it.