I have a 32 year old Toro with a 4 stroke Suzuki engine.  The deck is heavy duty aluminum.  Works perfectly and is a joy to use.  The self propel works great and has never given me a problem.  It is set up as a mulcher only.  I also have a 40 year old Toro with a Tecumseh engine that has BBC.  I use it for collecting clippings.  Despite all the Tecumseh haters, this engine runs well, starts easily, sips gas, and has been working for a long long time with only routine maintenance.  It does burn a teaspoon of oil every other use.  I also have a Honda 215 with BBC. It is a great mower, but heavier than the Toros, so it is not as fun to use.  I’d buy that Toro if I were you.