LOL, sorry Sam, I will never forget to answer a question of yours again! What a mess
I switched becuase I was getting some bleaching (zoox bleaching) from the 400.. I think it was too much light for the corals at such a short depth or the regular ballast wasn't running it at the right spectrum.. It ran great for 2 months with no problems and shortly after that, the bleaching began. I switched to 400w 10k Ushio and Had good success with recovery.
I thought I'd give the 250w hqi a shot.. I know I am taking a chance, but I'm willing to risk it as I have grown quite fond of the look of the radium. To my eyes, the 250 HQI is as bright or brighter then the 400w pfo.
A couple other things to note, yes the 250 is much cooler. I haven't checked my temp (usually don't very often) but to my hand, the water feels cooler.