AntDil,
If you are mowing reasonably heavy grass, you will have to slow down a little on the up hill, as the engine will start to lose some RPM's, but this doesn't hurt it at all. I mow with a 2810 HST with a 72 inch mm mower. I simply let off the HST pedal a little and it continues smoothly up the hill. More HP would aleviate this, but it really isn't a problem. A 2615 HST with a 60 inch mower would be the ticket if it bothers you. I hope I have been some help.
Galen LaWall
Your Mahindra Tractor Dealer
Batavia, NY 14020
585-343-0770