how many watts is a 8 tube tek in total, compared to your 500W now?
thats how much power it uses doesnt matter that its MH, incandescent or T5.
432 is a 8 bulb tek if i remember correctly, so thats not much savings in electrical energy, probably wont pay for the upgrade costs for at least a number of years.
But i would go with what you want your tank to look like, i personaly love the shimmer for MH and would never go with anything else, I also like that there are darker parts to put lower light coral in to give more contrast in my tank. But it sounds like you want even consistant lighting, so go with the tek its your money spend it how you want
