I am not a big fan of the mulch kits. They clog up under the deck really bad. If you do get one you should clean under the deck every time you mow. You need to mow really slow when mulching.
Hmm, my lot is small so for most of it, it will be slow but there will be a few fast back and forth laps. I have always mulched and to your point, I have a nine year old Toro 30" timemaster that proves your point. The deck is a year away from rusting holes through it. Maybe I should skip that mulch kit. I wonder what the cut looks like from the side discharge vs the mulch cut.
Gotta say though that the stamped deck on the Toro does not surprise me that it's rusted out. I can't believe the fab deck on the Dash would rot the same way though/ The wash port on the Toro deck is absolutely useless. I would hope the Hustler is a different.