Hmmm. I'm going to be the first to say that almost all of the bulbs in my house are CFL's. The ones I first bought are in the bedroom ceilings and they are dim when first turned on and take a while to brighten up. But the ones in my dining room chandleer and living room pole lamp are instantly bright. I couldn't tell you what the difference is, except for how old and new they are.

I agree about the brightness. If I want a 75 watt brightness, I get a bulb rated at 100 watt equivalent.