TTT for ya Phil. Gains are somewhat irrelevant when it comes to a tweecer in my opinion. Its a device to tune and get the car running the way you want it too. You can use a desktop but I think it would be easir with a laptop. That way you can datalog while driving down the raod and tune the car in real world conditions and not on a dyno.
Plus you can retune your car whenever you want and not have to pay dyno fee's.