Don't have the Shimano's but I did buy 2
pr of the Nashbar Highlander MTB pedals and the Nashbar Riding Sandles for our tandem.
Love both items. They are SPD compatible so we can use them spinning at the gym. The Highlanders are HEAVY (450 gms) but work great for the SPD and a regular shoe/sneaker. Large platform for support, but protruding allen screws for traction. COuld be removed if you aren't concerned about foot slippage.
Got the Nashbar Rodeo pedals for my son's mtb.
Ok, but not quite as good. They are cheaper, however. Clip in and release not quite as good as the Highlander. I think both pedals are made by Wellgo, a chinese company. Perhaps not the quality of the Shamino, but the Highlanders are very nice @ $50, IMHO.