Ed,
Enjoy your new purchase. You should get out what you put into it.
As far as the traction, I do have something to input. There can't be any more traction between a Fastrack and any other version if you're speaking about same GVW, same tire widths, same power to weight ratio, wheelbases, etc. There are two 54 Super Zs and a 54 X-One. None of them have any more traction than my RSD60 and I finish mowing my 3/4 acre in a few minutes less time than they do their 1/2 acres. I have a 250 foot 25 degree angle and theirs are all flat. I have a sprinkler system that makes the grass wet and I wait for the grass to dry before cutting.
However, I did, just for this thread, cut the grass wet and waited for it to get to 5 inches instead of 3 1/2 before I cut. The mower didn't have any signs of wandering along the angles and along the street has a short area with a fairly steep area to cut with a nice little 15 foot radius. Have to mow around a man hole on that steep incline. The mower did not care.
Hope the traction comment didn't sell you on the higher priced unit. Sorry I wasn't able to make the grass grow out more rapidly to do this test for you. No disrespect meant to Kraky. Just an observation and as an aside, I made a living doing the traction thing for many decades.
You may or may not follow motor racing. Autos, motorcycles and trucks. I designed chassis's, engines, intake and exhaust systems, ignition systems, breather systems for mud and swamp racers and rear axles for Fuel Cars on down to street racers. Here is where the traction comes into the equation: For mud and turf, if you're trying to launch a vehicle up a hill, you need horsepower as well as torque, to keep from cutting the turf, there is a fine line of tire width so you can get a bite and if the tire is too wide, it will spin. If it is too narrow, it will begin digging in and make a nice little rut, but then, you'll bury the unit. The Raptor SDs have very wide tires which in my opinion are best for your expensive sod due to less pounds per square inch of weight on the blades of grass. Adding weight doesn't necessarily make the traction better, it will, if the grass is wet cause you to spin more and do more damage to your grass.
I built quarter mile Wheel Standing Drag Cars known world wide, raced in Australia, New Zealand, England, Europe as well as all over the USA. I've attached a few of my productions since the early sixties. Traction is king for getting the job done and can even save your life on the side of a pond, drop off or hillside. Point to all this, the Raptor SD has the same traction as a Super Z.
Everyone is welcome to bring their mower here and we'll set up a scientific challenge to see if your mower has any more traction than mine. You may have more horsepower, you may have more rpm, but you don't have more traction than a Hustler Zeon with a full charge or a Raptor SD. Again, no disrespect meant to anyone. I speak from the scientific platform, not from personal reason to spend more money with the friendly neighborhood lawnmower salesman.
Hope you all have a great Father's Day 2016.
Max