I have always replaced my Grande bulbs with the clear 100w reflector bulbs, which are expensive.
I noticed that you can get frosted ones for much cheaper. I was under the impression that the clear reflector bulbs concentrate the heat better and the frosted ones wouldn't work. But I saw this online. Take a look at the circled comments in the screenshot attached. Has anyone used these frosted bulbs? Is there a difference? Does the light they cast look different?
I have used the frosted bulbs and while they do heat up the grande enough to get to flow the light is not as bright.
The frosted with lower light may have more to do with the voltage rating slightly lowering the wattage maybe your frosted bulb (like mine) is 130 Volts rather than 120 Volts. I have a "Kill A Watt" plug in device that checks how much energy something uses, I tested out my Grande with that 130V 100Watt bulb, guess what? It was only drawing 90 watts output! And the bulb's rated at 100W go figure. Then I checked the label in the Grande base, says "use 120V 100W" bulb so that must be why. So maybe the clear ones previously used are 120V rating and maybe truly 100W, although more expensive sounds like and not last as long unfortunately.