Thought I'd pass this along for anyone concerned or considering using Iwasaki Halides for their tank.
I was able to confirm with a tech from the US HQ for Iwasaki HQ, it appears that the Advance H33 MV electronic ballast 78E4091 (F can) is 100% comparable in bulb performance and output as the standard H33/M59 magnetic ballasts (core and coil type). This is for the 400w Iwasaki Eye 6500K horizontal base bulbs. The ballasts should run a lot cooler and with less noise.
Just ordered 3 of them off eBay, so hopefully next week I'll have some great news to report.
Still researching the H37 & M57 MV electronic ballasts for the 250's, actually know of a pair of M57's that are en route now that we'll be testing in a couple of weeks.