I have not tried the circle lenses, but I am a huge fan of Air Optix Color contacts. Everyday my eyes are a different color. I cycle through sterling gray, jewel green and sapphire blue. I don't know that they make me appear any more feminine per se, but they sure make my eyes look cool! I get lots of compliments on my eyes.
Perhaps I will get a pair of circle lenses and give 'em a go.