Absolutely ugly! We had CFLs in fixtures like these with bell-shaped glasses. GE Helicals. They still worked and all and they started off almost full brightness but they stuck out too much so we put in A-shaped MaxLite CFLs which look much nicer but take as long as an HID to warm up!
I wouldn't want clear incandescents in this because of the glare. I only like clear lamps in fixtures where the lamp isn't in direct view. Although I am warming up to clear lamps (now that they're banned lol).