The engine revs better past 5k rpm, feels more like natural inspirated engine, it's more fun to drive on a twisty with less boost compared to stage 2. Because you are revving higher the car is thirstier. As per performance estimates in MHD site,. Stage 1+ has more power but lesser tourqe compared to stage 2. For thermal reasons I mostly use stage 2 in cooler seasons and stage 1+ in summer. It's definitely difficult to decide between them though.