I'd rather get beat by a galatic emperor if I wasn't Vegeta. Being Vegeta I'd rather lose to 18, can't be the Prince (King) of Saiyans and get your ass beat by your greatest oppressor. It's like Mike Tyson getting punched out by a slave master in the past.
Though 18's must have been a heavy blow. If being defeated by a woman isn't a big deal for him, being effortlessly tossed aside by a robot after finally achieving his Super Saiyan form..
__________________
"Gonna need more chloroform..."
"If you look down on us, judge us, condemn us... then you shall fear us!"
18, it would turn me on a little bit to get ****ed up by her if i were vegeta. but if i wasnt freiza, hes weaker then androids and therefor it would take more time to put damage on me that might tire him out or waste his time...
Frieza's beating was more brutal. He was being tortured physically and emotionally by the being who annihilated his entire race and oppressed him his entire life. All of that after having rubbed in his face that he was not a SSJ.