I own a pair at the moment. The M74's are my first upgrade from some really cheap one's I bought first.
I have to say they sound really REALLY good to me in comparison to the cheapies. It really changed my perspective on sound quality and has cursed me with a permanent case of up-grade-itis.
However a few reviews I've read around the place have complained about the high's not been clear enough, but the mid-range and bass are pretty good.
I'm sure there are better speakers to be found, but these should keep you happy for quite a while.
BTW, which ones are you looking at?