well the 09's have the ls3 motor in them they are just tuned down from the factory and rated at 395hp. At the wheels they get about 315rwhp. Now such as an 05 like I have, they have an ls2, but yet again they are detuned to 345hp. They only put out about 255rwhp. If your power hungry like I am, go get a simple dyno tune. And if they know what they are doing you could get an easy extra 35 to 45rwhp.
Either way, you can get your h2 to keep up with the 09's. Get rid of the stock clutch fan and get dual electric fans 15hp. Air intake 10hp. Shorty headers 25-35hp. Exhaust 5hp.
So about 250.00 for the dyno tune and about 2500.00 for other parts and you'll have the same amount of hp as a stock 09. Then if you really want the power start with the heads, cam, supercharger, etc. Then the tranny with about a 3200 to 3600 stall and you got a h2 with about 550hp.
To me it would be worth the money to fix up the used h2 rather than pay for a new one.