After running tx's for I don't know how many years and cx's for seven years the aps is in the way better spot. It ability to smooth out the crop flow before it hits the main treshing cyclinder makes it much easier to run the machine at capacity without the engine load bouncing all over the place. In canola is where it really makes the biggest difference in lumpy swaths and in wads there is just no comparison. I'm sure some of it has to do with the hydraulic pressure breakaway on the concave but the aps still makes a bigger difference. I don't think the rotary seperator is a bad idea I just think the cx would be better off with it up front as well. The other good part about the aps is that is runs slower than the main treshing cylinder, therefore making crop acceleration a lot more gentle than from going straight from the feeder house into the main threshing cylinder which is why we are able to run way higher cylinder speeds with our lexions and still not crack canola. Which of course the cx's are well know for, although not as bad as the tx's. The only thing that makes my opinion a little bit off is that of course we have rotors behind so I can't comment on what system puts more grain over the walkers. A combine specialist from claas told me that the claas rotaries save a lot more grain than the claas walkers. So take that for what it's worth. I can say for sure that the claas system is a lot better and smoother at taking the crop in.