The Turf-Master is a great mulching mower and it leaves one of the nicest cuts you'll every see. You can't compare the Metro to the Turf-Master even with the same engine, that would be like comparing your Honda to my Cub Cadet because it has a Honda engine. The Metro is a single blade mower and wasn't the best thing that exmark ever came out with. The Turf-Mater is a twin blade mower with a 18,000 BTS and a completely different deck, and it bags well. As far as side discharge goes that I can't really say because I've never really used it.
I had The G1336 Walk behind and sold it when I purchased the GS because it was a WB also And I didn't need two. To answer Lawnboy 18 The Toro Grandstand does an excellent job mulching the Turbo force deck is a better than any Velocity deck I've ever seen, but does it compare to the Turf_master, He!! no but then again no walk behind or ztr has a nicer cut than a push mower is going to have.
LMF the other thing I may add is to remember if you decide on a 36" WB is to make sure it's hydro drive and not Belt drive because the belt drive even though it has a reverse setting it doesn't have a real reverse, it operator assist which means you pull it out or backwards if you get into deep grass, they will work you to death.