Pros: Far superior to just pounding, enhance marinade penetration, REALLY cubes the meat
Cons: The only way to clean it effectively is in a dishwasher--too sharp to clean by hand
I've owned this tenderizer for about a year and a half. Alton Brown talked about the joys of a 48-blade cutter for turning cheap, tough pieces of beef into actually cubed meat -- meat that's perforated to make it tender. It had good reviews on Amazon and was fairly cheap so I bought it. Now can't imagine being without it.
It's very simple to use. Simply press down and the 48 blades cut through the meat, piercing connective tissue as it goes. Using this and a mallet turns a tough chunk of london broil into an easy-to-chew cutlet. 48-blades plus a mallet turn a boneless pork loin chop into tender schnitzel. Pierced meat soaks up marinades like a sponge!
It's easy to clean although you can't really wash it by hand; you need the dishwasher for this. Simply rinse it after use with the blades exposed -- don't touch them -- you WILL get cut! Then put it in the top rack of the dishwasher. It comes with a protective cap to store it with no blades exposed.