How much of a difference?
After having used the cheaper stuff in my 107 once upon a time and seeing how it operated and then going back to genuine IH HYTRAN in the last change there is no comparison as far as I'm concerned. The BIGGEST thing by a mile is the way that regular hytran will absorb water. It can handle water up to 1% of its volume and have no harmful effects or additive fallout. Most hydraulic transmission oils have problems at 1/2% or less. This is of concern on our hydrostats as they will absorb moisture over time especially on a tractor with front hydraulic outlets for a snowblade. While it makes no difference on our cubs it also helps with brake chatter on wet brakes and slipping powershift clutches. I know of people that have big JD tractors and have dumped their JD Hy GARD fluid and swithced to IH HYTRAN and the afformentioned problems went away when they did it. It may cost a little more to start but if using another oil leads to problems down the road I say it's worth it up front to prevent it.