I generally can tell when something has been microwaved - scrambled eggs at a breakfast joint, for example. Sometimes it affects flavour, but sometimes it does not. Regardless of whether it lowers the quality of a dish, it is something I am extremely critical of - even though it is faster and (probably) healthier than doing something on a grill, in water, etc.
It seems to be an increasing part of restaurant cooking culture. Cerca/Sysco actually sell 'mussels' that are flashfrozen and designed to be cooked by 10 minutes in a microwave at high power. While it allows restaurants to carry an item that is usually restricted by season, volume, and turnover, it also freaks me out like you wouldn't believe.
I would like to know how we all feel about microwaved foods in our restaurant experiences.