If you check on the MC website, you will find out more about the 209. However, the 2 boats are pretty close in size and function. The Outback will have a better slalom ski wake and the 209 will have a better wakeboarding wake. In MC sales, the 209 was not a good boat and that is why is was only made for a few years. In truth, the 209 does nothing great. If you have a family, compare the freeboard on both. The MC will probably be a bit larger and make the St. Johns thing better.
If I were looking at both boats, condition and options would be a key for me. Also, check NADA for a price comparison.
1997 MasterCraft 205
2008 Moomba Outback
1999 MasterCraft Sportstar OB
1992 MasterCraft 205
1999 Malibu Response LX
1987 Marlin Magnum Skier