I have HIDs in all 6 lights and they're a PITA (Pain in the @ss). When the metal HID boxes come into contact with ANY part of the GTO body, the lights come on (or the boxes come on if the lights are turned off) and it kills my battery. I'm currently looking for a way to insulate them without overheating the HID boxes. However, they do light up the world. I had HIDs on my last two vehicles and I won't go anywhere without 'em. I think they're a safety item that should be required on EVERY CAR, TRUCK OR SUV sold in the world. They reflect off of road signs and other car/bicycle reflectors so much better than halogen lights. The yellow lines in the middle of the road and the white side-road markers are so much brighter and more defined, which in turn makes driving safer. So, for me, it's a no-brainer to have them, but be warned, they do come with special issues, and you're going to get bright-lighted more often if your lights aren't properly aligned. One thing I LOVE to do is return their "kindness" with 6 lights full of HID fury (I removed the fuse which makes the fog lights go off when I click on the high beams), which really lights up their universe.
Anyway, you may or may not have the metal to box contact issues, depending on which type of HIDs you get and all that good stuff. Hopefully you DON'T have these issues, they're a severe pain in the rear.