DS 30 Lap counter timing system

If any of you guys are familiar with this system, I'd like opinions and what you think about it. I can get a 4 lane system pretty cheap from one of the locals, but will need to buy correct hook up cables. He has the master box and an extra box for lanes 3 and 4. Price is cheap enough, but not if it isn't really easy to use.
thanks
Mattb
thanks
Mattb