Anyone use a line lock/roll control

I have one but dont use it to launch, I use mine to warm my tires without killing my brakes and clutch. I have the SLP and highly recomend it, its a direct bolt in with no lines to cut. Easy install took about an hour or so and works great.

So you only use it for the burnout but not the launch? It seems that is would be brutal on the front brakes during a burnout (just like a break stand) but give you a higher rpm launch, but I don't have them so I will have to ask you to explain further.

I race pro tree you dont have time to set and wait. As far as the burn out once there spinning your not really holding back much and with the MTs and water it doesn't take much to get them spinning. Besides with a 150 shot you dont launch at very high RPM, unless you want to spin to half track. Might not be the best way but it works for me. My 60' are normaly 1.6x with my best being a 1.60 on drag radials, and my RT's are .4xx most of the time with .400 being perfect so I aint changing.
Also using the linelock keeps you from dragging the rear brakes during the burnout.