I have a question regarding mowing speed. I am primarily interested in the Fasttrak and Minifastrak. I see that both of these mowers will go up to 7 mph. My yard is relatively smooth with a few small dips and bumps. At what speed can I reasonably expect to mow. Also, does having a mower with a suspension seat or suspension enable one to mow very much faster than the speed at which one of these mowers would mow. I am mowing approximately 1.75-2.0 acres with plenty of trees. One other question: which Kohler engine is available on the Mini- and Fastrak (command vs. courage). Thank you.