Who has experience with a current generation 36" Gravely WB? I'm looking at a hydro fixed deck with 15hp Kawasaki. For anyone who has used this machine, here are a few questions: -- Can it actually mow at it's 8.5mph top speed? -- Have you tried double blading? -- What mechanical probs have you run into? -- Is the 15hp enough to run a hydro, double blade, and go 8.5mph? -- Is $4,150.00 a fair price? -- How is quality of cut? Thanks!!