I'm hoping I can get a much smaller system for mine. The one that came on my mill only takes up about an extra half inch. I think I can work with that. I've also taken the locking nuts off my cross slide dove tail screws and put some carb needle springs on in place of them, for ease of adjustment. Don't have much time on them yet, but I hope it works good. One of the screws is right under my compound slide and its a bear to adjust. Now it's much easier!I wanted to put the DRO on the tail stock side but it would have limited the tail stock travel to the work and access to the carriage lock. It fits under the 4" three jaw chuck without a problem as long as the jaws are not sticking out too far. I really need to be careful when the 6" four jaw chuck is on. The chips land on top of cross slide and RO scale. I have a shied on the the scale and there is no problem with chips.
The scale takes up about 2 1/8" so that's how much space would be lost between the carriage and the tailstock. I like to keep the tail stock extension as little as possible when turning.