I have had the Toro with the cast aluminum deck. After I repaired the height adjusters a couple times, I had to replace the deck because the aluminum wore out. I wore out the second deck and got rid of the machine. This was using it strictly for home use.
Now, I have the commercial Toro ($1000) with the steal adjusters and rubber tires. The adjusters work tough but it is only 1 year old. I believe the rubber tires (not plastic) will take a lot of the rattle out of the ride so the adjustments do not wear as fast. I know it is day and night compared to the residential mower.
By the way, my "old" Toro, the one I went through 2 decks, many adjusters, and three sets of tires lasted almost 20 years.
I try to get along with people..... it's just so damn hard weeding out the IDIOTS!