I have ridden with the Red Shift stem for approximately 500 miles. Except for when I am using the inner bar ends, (really just Specialized carbon bar ends mounted inboard), I never even notice that it is there, (other than that it does a very good job of relieving the harshness of the ride. I also added a Cane Creel eeSilk carbon seatpost.
About half of my riding is on dirt/gravel roads along the New Hampshire and Vermont border, half way up the state. The addition of these components has made a huge difference regarding comfort with no noticeable loss of power or control and with very little in the way of a weight penalty. If anything, control is improved because the largest mass, (me), is not getting knocked around nearly so badly.
I have made other modifications to my cockpit as well including Salsa Deluxe Bend bars, SQLabs 710 grips, Garmin 830 GPS, relocating the Yamaha display to the front of the handlebar so that my knee doesn’t make contact when riding up a steep hill out of saddle and I also machined a Delrin adaptor to mount my headlight to the GoPro time mount on my Garmin mount.
The SQLabs grips felt a little odd at first and took about 60 miles to get used to, but now that I am accustomed to them, I do like them Very much.