Thanks guys! That helps a lot! No, I'm by no means a street racer. :) I baby my LS just like it deserves, though I do have a heavy foot. I'm not into full throttle take-offs or quick stops, though. I love and respect my car very much and like to think that I take very good care of it.
That said, when I got my car back from the dealer yesterday (which is when they told me I'll need new pads at my next service), their explanation for the loud squeaking noise that I hear at low speeds, particularly when the brakes are cold, was that the rotors are "glazed". I also thought that I had felt some slight grinding when coming to a stop, however I was informed that this was just the glazing on the rotors, and no metal-to-metal contact was being made. I think the receipt said that I have 5mm of pad left, and the minimum recommended is 3mm. Is that accurate?
I like to think that I can trust my service adviser, as I've been using him for almost 4 years and feel that I've always been well taken care of, though I've paid for it.
I'm intrigued by the idea of servicing my own brakes, however that's just one more thing to add to the list of things that I don't have time to do. Know what I mean? Where would you suggest that I take the car to have it done (other than the dealer)? I found a good independent Mercedes mechanic on Yelp for my third car, which is an old S Class diesel. I guess I'm just nervous about taking the car to someone that I don't know. One thing I've learned to do on the Mercedes is order my own parts online and then just have the mechanic do the work. That has worked out well for me.
Again, thanks for the feedback! I really appreciate it!