My preference was the 850. I used a 750 when I first started and it worked ok, but the ANR was definitely nice. The telex lightweights are comfortable (and don't require batteries which I think is a bonus), but they are lightweight and prone to getting beat up overtime in a flight case, hence my comment to budget to replace about every 3 years.

I've used the 750 or 850 on all of the various jets I've flown (CRJ, Citation, CL604) and they work well.