Stage 2 cams just give a flatter torque curve, more torque over more of rev range over the stock 2.2 n/a cams.
Stage 3 open up the top end more and give same torque gains as stage 2.
really need to start talking in degrees and lift. the stage tuning is not real world and can often be vastly different between tuners.
saying this so you get the cams you want for the power you are after.