Not sure what the small ones have,what i use or would want is ability to set roll out and set dial ins so you can stagger tree and or go pro tree if your into the electronics racing which mine does.The big thing i find is you have to get the rollout set to match car so what you do on the practice tree transfers to track after that its learning when you leave/repetition.I don't get a lot of seat time compared to others i race with,it's 1.5 hrs each way plus the money so i have to use the tree to kinda make up for that but its still not the same,heat of the moment nothing on the line,doesn't matter if i bulb on the practice tree but in elims its different.Hope this helps
