It's basically your preference... you wouldn't go wrong with either machine and they are both excellent units. Since they are slightly used, with only 150 hrs, odds are they are both in virtually new condition, but be sure to check them over and ask why they are up for sale.
As for features, again it's your preference. Regarding foot pedals and ergonomics, well not everyone favors the JD layout, so try them both and decide for yourself.