150w HPS

Hey Guys I'm rebuilding my grow cab some time in the next few weeks and Im wondering if its worth it to ditch my 5X42w CFLs for a 150W HPS lamp My box is
2ft X 2ft X 4f I have problems heating it in the winter and as well keeping it cool in the summer. i use PC fans and a heating mat for the roots in case that matters at all. can anyone give me an educated opinion?

9north, I have a 2x2x4 box myself. I run a 2 foot 4 bulb T5 in it with good results. The 150 will be great in the cool weather when you need to push the temps up, not so great in the warm months. Your room temps are going to dictate a great deal, you can't cool a 90 deg box with 85 deg room air. I have the same issues in my workshop with no heat or a/c.