My instructor put a 20kg weight in the passenger footwell of the R22 to try and even out the weight inbalance issue. This did the trick as I didnt notice much difference at all (even though my instructor weighed a whole lot more than 22kg).
The key is to ensure that you are lifting to "light on the skids" where you balance the cyclic and then lift from there slowly. That way you should have compensated for any C of G issues prior to getting in the air and you shouldn't have any excess power issues as you gently bring it up. Easier said than done of course at 20ish hours.