Anything is better than CFL's. They do the job but not anythign compared to the HID lamps (MH, HPS) MH has the right kind of spectrum that makes flowering optimal, CFL's just dont put out enough light
I would go for a HPS if I was you. MH isnt too hot for Veg stage, but if you already have one then your set with both. HPS is def better way to go if you dont have a HID light
MH does have a better spectrum for vegging the MH. But, MH gets way way hotter so you have to put the plants further away from the bulb which means less lumens on your plant. Lumens drop fast with distance. With fluro's because you'll use more bulbs because of their lower Wattage per bulb so you get more 'suns'. Meaning, less shadows, better spreading of the light which is good. So you see both of them have their charms. Many people I see on this forum use fluro's for vegging (and some (me) even for flowering) with great results. It's more of a practical issue I guess. If your grow box is up the attic where it gets pretty warm during the day get fluro's for they don't get so got. If you have a large grow room you need MH bulbs to avoid spending too much time on wiring and mounting many bulbs.