This mower is built like a tank, which in my case is bad, because it won't wear out so I can replace it. Bad Boy seems to have a weak link in this mower in the blades. With new blades that measure 20.5" tip to tip, it cuts pretty good. After 4-6 hours of use, the blade may show some wear and only measure 20.3" or 20.4".
At this point, the mower no longer cuts grass acceptably at any speed. It leaves much of the grass uncut. The blades must be replaced before you can again cut grass. When I purchased this mower in 2010, the Bad Boy website suggested taking your blades to an authorized dealer to have the sharpened.
At the time of this review in 2013, the website suggests replacing your blades rather than sharpening them, so it looks like they now realize they have a weak link in their mowing decks. I now buy a lot of 12 or 15 mower blades at the beginning of each mowing season and the mower works okay, but for $8,000 you'd expect a little more.