I don't know of the 125 watt CFLs, but I think 30 watt and properly working 40 watt CFLs are plenty bright. I think if you increase the wattage higher, it just adds more spirals (more light) but not making the light any brighter, if that makes sense. Do a test with a 13 watt CFL and a 26 or 30 watt CFL, and tell me if there's a difference in brightness (there should be, but it's definitely not twice as bright). On a side note, my 40 watt CFL is faulty and not very bright.