I have a Touch DRO on my lathe/mill
I can't tell you how much it's improved usage on my machine.
I even added a small case to house the electronics.
My only issue, and I'm pretty sure it's in my components, is that sometimes the horizontal axis resets to some off the wall number when I power on the machine. I've gotten in the habit of looking at the display before I hit the power switch to make sure I know what it is.
Other than that, I'm using 3 axis and a speed reader. The reader is super simple. Just a $2 hall effect sensor and 6 magnets glued to the driven pulley.
AWESOME value!