Disc mower conditioners cutting clean at slower speeds

The offer I made on a NH 499 was turned down and I'm not sure I want to spend much more than I offered. I have been thinking that if I could get a decent trade in on a piece of equipment I have been trying to sell I might just be interested in buying a new disc mower conditioner. I would be buying a machine with rollers since I grow a variety of different crops.

My concern that I have with a disc mower conditioner is getting a clean cut in lighter crops.....especially at slower cutting speeds. Most of my fields I can run 6-8mph but there are a few hillsides that I have to go slower on to keep from being pushed around and possible ending up sliding into the woods. I have heard that in lighter crops the faster you cut with a disc machine the cleaner it will cut but on my hillsides this isn't an option. Will this be a problem getting a clean cut in light crops?

I'm growing more and more alfalfa every year and later cuttings are many times short and thin from summer drought so getting a clean cut in alfalfa is very important.

Disc mower conditioners cutting clean at slower speeds