I'm in the "stay away from them" camp.  But at the same time I can show you and others here several JD 86 series that have given their owners very little trouble.  This spring we custom spread some fert for a farm with a pair of 8640s.  Both have over 10,000 hrs with just one engine replacement done on both of them and thats it.  The JD 30/40/50 series are kind of like IH TAs in my opinion.  They will give you good service if you baby them, treat then nicely, don't abuse them, or pull the guts out of them.  They can't take the abuse that a Steiger or Versy can.