It's a matter of personal preference. I have flown the T-Rex in 15-20 mph winds, and it does okay, but I am used to flying in windy conditions. That said it's much more fun when the winds are calm.

My Raptor 50 handles up to 25 mph winds quite well, but it's about 6.5lbs and FWIW, the same price ready to fly as a T-Rex SE.