I have a Hartge bar in the front, no bar in the rear.
When I first placed it, I wasn't very happy with it. The car had a tendency to understeer more and I don't like that. It does sharpen the turn-in responce because the car is more rigid, but once that fase is out of the way I found it to be troublesome. So I removed it.
A couple of months later, I placed excentric M3 control-arm bushings -> these add more caster to the car, which also increases the dynamic camber in corners. So the car had more front-end grip.
I then placed the brace back and the end-result is a more balanced car in the corners.
So the best answer to your question is: if you drive fast, even on public roads, but don't really have any other mods, I wouldn't do it. If your car is setup for some fun, I do recommend it.