@rrcoolj: i keep all kinds of reptiles over 14 years now and I have used all kinds of lamps since then. Regular light bulbs, flourescent tubes, mvb's and metal halides, etc... Besides that I work in a big pet shop where I can test all kinds of different models cause we have a herp, freshwater and seawater department. That's why I am confident that I know what I say. I know that mvb's WERE used for a long time, but now there is better material available, so why not use is? I know 250w or 400w lamps which are used for seawater tanks are too powerful for many herps, but there are models with 70 and 150 watts which are perfect. The german company that produces the metal halide lamps for herps even offers a 35w version!
I am glad it works for you but MVB works for me and many other reptile lovers. And they are still used now by many people. Plus as mentioned they are harsh on your electric bill. Plus IDK about others but there is no way I could find a low watt metal hilide anywhere near me and I don't even know where I can find one online. I am not doubting your method but I am saying MVB's work and work well for many people. I personally recommend them.