I did a search and didn't find any info on using s3114 servos on a 450, so I guess I will post up some.
I recently bought a Rex450SE off the classifies and being as I don't have a whole lot of money to play with, I am cannibalizing my King2 to get the Rex running. I have run S3114 servos on it for about 200 flights and have really liked them. On paper they are an awesome servo but as most people know, they are not easy to mount up and the servo arms are a little small and thin. Anyhow these little guys are very fast compared to the average HS65, so they should make for some very quick cyclic movements.
That all said, I now have a full set mounted up in the Rex. The install was very easy and probably easier than any other servo I could have used. You can install them into the frame in any order and from either the opposing hole or from between the frames, they are that small. In fact I installed the top servo first and then installed the bottom servo and even left the servo arm on it while I did so. Anyhow placed a screw through the hole closest to the servo arm and then whittled a "U" in the end of the other tab and used a screw with blue washer to "pinch" it in place. They seem to be very solid and probably more solid than the servo arm can handle. Then I installed the ball in the hole I used to have a Blade400 ball in that ran the cyclic on my King2 and put the nut on the back because I had it. The arms do give a little but I am guessing it will take some fast and hard movements to feel it. For basic stuff I think/hope it will be fine. I guess I will find out.
Here are some pics
Team New Mexico