The hsv is nice, but it's like a boost based controller in the way that it's not needed, and costs a lot of money. Although I have an hsv, if I had to do it all over again, I would go with a basic dual or single stage system. Not saying that I don't like the hsv, but the good old bang for the buck question comes up. If I could spend $500 instead of $1000 and get 90+ of the effectiveness, should I do it? Do I need the possible extra 10%? If I can spend $250 instead of $500 and possibly get better effectiveness, should I do it?