I've been flying DF jets for years off one of the worst fields out there lol! Check it out,
www.korc.ca . Older kits like the Byron F16 are great even on less than perfect grass. I always used a BVM remote mix valve and made sure I was at full RPM on take off. The Top Gun Mig and F15 are also really good grass jets. Use positive incidence on the gear and hold up elevator until you rotate. Kind of like float flying
Just read a little futher down the posts. Ya, maybe just get a DV8R. That's what I did and I won't be missing those DF engines!
Shaun Bell