Since the factory does not offer a FEL for those tractors I think that speaks volumes about their position on FELs. With 60% of the weight on the nose, I don't know how a FEL would ever work properly.
They do spec FEL for them. Sigma is one. With proper counter weights in the rear they do fine. Just don't go lifting the front end off the ground as you are courting a failure as we have all read.
My AC Tigretrac has done over 3000 hrs. Only problem I've had was stripped gears on the front drive (caused by a lousy mechanic doing a clutch replacement).
It's absolutely unbeatable for hillside work. I love the reversible control set up. I've fitted it with a rear loader (Cadloader made by my neighbour who's a pro welder).