I just happened to talk to a dealer today about the mini Z and the super mini. He quoted me me $6800 for the 24 hp w/ 52 deck for the mini Z.
Mini Z Super Mini Z
19 hp/ 44" ~$5750 ~$6300
24 hp/ 52" ~$6,800 ????
I have no personal experience with hustler, but from the comments on this site, Hustler is very well respected and is considered to have the best warantee in the industry. Check the Hustler formum for more a lot for information.