i have never used miracle mud. but a deep fine sand bed (oolitic) would be cheaper and just as efficient. MM supposedly release some trace elements back into the water that are beneficial to our systems, but the cost of the stuff is quite extreme.
I will defend this stuff till I die. Miracle Mud!!! Some say its just dirt I say I love it. I have a sixty gallon with a 30 gallon fuge with Miracle Mud. I have no skimmer or any of the other gadgets everybody buys. I have live rock,live sand and do water changes every 2 weeks of 10 % about 8 gallons. I have no hair,bubble,or any other problematic stuff. I do get an occasional bloom of something here and there but then i do a 20% chane and a little clean up and never see it again. It isnt the cheapest stuff and they reccomend you replace 50% after the first year. I will be doing this in a couple months.There is more then one way to skin a cat so Im sure other methods work well also but this has worked for me.