I have a Conquest 4.5-14 with the rapid Z 800. The best scope I've had. The reticle matches very well with high velocity rounds. It seems to be set up for rounds in the 3200 range with b.c.'s of .450 or so. The rapid z 600 is set up for slower stuff, 2900 range I think.
They have a calculator on their website that you can put your speed, bullet, etc and it will spit out the values for each line, and tell you what power to set the scope on for the closest fit.
No, it's not as precise as dialing turrets, but it's pretty darn close for the intermediate ranges.
All in all I wish I had a couple more of these scopes.