Just switched to Looks on my road bike and Love them so far. I still have SPDs on my winter commute which I will probably keep since the MTB shoes that fit the SPDs are bigger - and will accomodate heavier socks! I'd say go with cheapie shoes for spin class and stick with the Looks, as long as that's what you like.
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"