I think it depends on how much you are mowing. I set out to buy a SCAG or Exmark a few years ago and ended up with a JD 425. The main reason I changed my plans was because of looming layoffs at work, but when I really got to thinking about it a commercial mower was hard to justify for an acre and 30 hours per year of use. I then started looking at residential models and went to get a Exmark residential model and ended up bringing the JD home. There were things I liked about it better than the Exmark residential and the SCAG residential was about $1,000 more.
Do I wish I had bought a commercial, yes, but just because I like heavy duty well built machines. But for the money I have used mine 4 years and have 100 hours on it without any problems (two droughts have kept the hours down a little). An hour of use per week it is just hard to justify a $7,000 mower when a $4,000 is doing a good job and is going to last a long time in that situation. Pick the machine to match the work I guess is what I am saying.