I use SPDs only cos I got them cheap from a friend. But even with SPD you won't clip out of them brakeless. The only times i've clipped out is dong stupid **** Like nuts to the stem pedaling backwards stuff. Regardless mountain shoes would give you the edge cos you could walk in them a bit. My road shoes are annoying but I love clipless so much I don't care. Clips and street shoes are so inefficient I don't know how I ever road on them