FYI. I have put 100 miles on my new Wheeltop EDS TX Disc kit. I am very impressed with the quality and how good the EDS TX is working. The only thing I dislike is the ergonomics of the shift paddles on the right shift/brake lever. My fingers are having a hard time hitting the right button now and again, and more often on single track trails when the bike is bouncing around. I presume that as I get used to the paddle operation, it will become more second nature and I will mess up fewer shifts.
I was a lot more impressed with the disc caliper's stopping power than I thought I would be.
I was thinking about the ER9 or ERX, but I am sold on the EDS TX kit now. I hope the WheelTop products become more readily available in the USA, I have another bike I want to upgrade.