I have had a GY401 ever since I started flying helis some 5 years ago. I used to install it on my Sceadu50 with Futaba 9254. I am now flying it on my Trex500 with Futaba 9257. It is reliable and easy to set. I however would not recommend it for a Trex450 as it is expensive ($8xx) in terms of the overall cost of a 450.
I am now flying my Sceadu50 with GY611 with Futaba BLS251, which is much better for 3C.