I commute in Boston (frequent stops, sudden stops, chaotic traffic). I use clipless. I love it. I don't "lose seconds". I don't fall over. Your mileage may vary. In fact, everyone's mileage varies -- it's just the people who like to say stuff like "it's not worth it" who don't get that. They've decided that it's not worth it for them -- you will hopefully make your own decision.