I dont think the difference is so much with the bulbs, but the ballast you plan on driving them with.
there is more color varieties with mogel and the bulbs are a little cheaper (I think)
I agree. I like to overdrive SE bulbs with an HQI ballast.
DE has more light spread whereas HQI is directed more downwards.
Most of this will depend on the reflector, but I am pretty sure that if you removed the reflectors, the spread would be nearly the same.
HQI has higher par in most cases
Yes, if you're reffering to the ballast, they do usually drive the lamp better than other ballasts.
With most bulbs.. MOST bulbs.. an HQI will overdrive a bulb, a standard will drive a bulb, and electronics will underdrive a bulb. There are a few bulbs that run better on an electronic vs a standard, but I dont think that either standard or electronic will overdrive a bulb like an HQI ballast will.
I dont think the corals will make a difference in your choice of ballasts/pendants but moreso your set-up/application/space.
I have 16 halides set up at the moment.. HQI ballasts, standard ballasts, and electronic ballasts. Some were DE bulbs, some were SE bulbs.. I never liked any of the DE bulbs that I used, and now every one of mine has been switched back to SE (single ended) bulbs.
Good luck