You should be very pleased with the 60's.
As to your question about carpeting. Everything in your room effects the overall sound of your speakers. If you had nothing in the room your speakers would be overly bright and the sound would be so reflective that you wouldn't be able to stand it just like when you take everything out of a room to paint it and try to have a conversation with somebody in the room. It just echoes all over the place and is totally annoying. Anyway I would not put my floorstanders on a stand because they are their own stand. They are that height for a reason so that the tweeters are positioned at the same (approximately) level as your ears when you are seated on the average couch.
Does the carpet absorb sound? Yes. Will it absorb about the same amount of sound wether your tower speakers sit directly on it or two feet above it? Yes. Are the drivers on the M60 placed high enough so as not to be overly absorbed by the carpeting below? Yes. Do you need stands for your tower speakers? Nah. . . IMO
