Predictably I'm going to say r tech....a friend has a stage 2+ GTI with revo software l, mine is r tech stage 2 gti and there is a massive difference between them both...mine drives nicer,much easier to get the power down,pulls a lot harder for longer and is better on fuel than his revo...... if you went for a revo or Apr within you will be happy with it.if you go to Niki then you will be much more than happy..