I have about 13 hours on Raptor SD 54 and wanted to post a short review. All I can say is why I didn't get ZTR sooner. I had lawn tractor and it's night and day..
I had issue at beginning:
http://www.lawnmowerforum.com/hustler-forum/28396-need-vent-about-new-raptor-sd.html
Now I installed mulch kit, heat shield and engine guard.
If you read my original post - I was impressed with how pro's handle my neighbours yards. Now my yard looks better! And I already saved tons of time. With mulch kit Raptor does excellent job. At first I had to scrape deck couple times after trying to cut wet or in a morning. Or when grass was growing fast. I was kind of hoping it will take care of leafs and it exceeded my expectations. Everybody blowing or collecting leafs this days, I used to do this too, it was taking me maybe 15hr of work every season with big backpack blower. Now it mulches so well that I have perfect lawn, rarely I need to do 2 passes. Leafs clipped to about 1/4 inch size and barely visible, you have to look for it to see. If I understand it right - it is good for the grass too. But final verdict on leafs will be in a spring when grass starts growing back.
I was worrying about hill - no problem. I feel very comfortable turning on a hill, going sideways, etc. It handles it very well.
Negative thing comparing to lawn tractor - ZTR uses much more gas.
I guess any decent ZTR would do this, but so far I'm really happy.