Thrashing the Rover today in mulch mode.
I have had this since 2014 and has been WELL used (check out the bald front wheels). Its had only one drive belt in that time but two drive system overhauls and a set of new rear wheels (they are cogged as part of the self-propel system). Apart from that, oil changes every few months.
I'm not a big fan of the Kohler engine as its a bit finiky to start and has always used just a tad of oil, no smoke but I keep an eye on it more that the Briggs engines I run.