I did half step on my early build. I liked it, although the shifting was a little complex.
I went so far as to create a spread sheet to calculate the gears...that way I could make changes either in front, or rear (virtually) to see how the gear ratios and shifting should go.

It would be easier on a bike with Brifters I would think. That way you could shift both front and rear with little effort.

In the end, I have done away with it, I am sure there are far more experienced riders that can give you better input...as I am still a newbie...I think.