I've tried alot of different flat cycling shoes (661, 5 tens, etc..) and the Shimano SH-MP56L shoe are by far the best shoes I've ever used.
There very lite but extremely durable! Very easy to clean, The lace cover work great, and there grip on flats is amazing! There very comfy cause they run alittle wider than most cycling shoe and they also breath very well! I can't find any problems to report about these shoes and will continue to buy and ride with the SH-MP56L shoe until shimano stops making them! Amazing shoes!
Also, They make SPD versions of these shoe for riders the like to be clipped in. There called the SH-MP66L. I help this info clears anyones questions.