Strengths Great Speed, and a strong healthy engine (Gas).

Weaknesses Design problems. The 72" deck bolts break. The pulleys on the belt system fail because of bad allignment. The new hydralic deck lift system is weak and has already failed. In first 15 weeks of ownership the unit was in the shop for 5 of those weeks. John Deere did a free upgrade on all the problems and the latest 850 units from the factory have the fixes.,

Overall Solid frame, great speed and a very nice unit if it would just not keep breaking down. The local dealer gave me a completely new unit after 60 hours of run time.