I purchased a TN75A with a 7ft Brown HD rotary cutter. I use it on 10-15 deg slopes with no problems. If the ground is wet, make sure you keep the FWA locked in to be on the safe side. Also, varying your speed and the direction of cut makes a difference. I run perpendicular to slope of my hills (up and down) as opposed to parallel just because I feel a little more comfortable with this method, even though it is a little more work and takes more time.
I also purchased a 7ft RC because I did not want my mower extended out past the width of my rear tires. The Brown 484 is also a heavy 3PH unit at 1350lbs - you can check them out at
www.brownmfgcorp.com to see additional specs.
A TN70 or TN75, will be a good choice for mowing, but consider also that the TN75 comes with higher flow hydraulic pump as std. equip. and has a few extra HP.
The decision based on cost differential when I purchased was a no brainer, but results will vary depending on dealer inventory, etc.
I also looked at the Kubota 6800 and JD5420 - the Kubota was OUT for me due to the levers being located on the floor between your legs - The 5420 was about $3k more
The power shuttle is another option you may want to seriously consider -
Hope this helps - and good luck on your purchase. /forums/images/graemlins/cool.gif