I have the G-15 as well (the 1st Gen with more macro keys) and I love it. The few Microsoft keyboards I have owned in the past all did their jobs, but they never really impressed me. They worked and that's about it. My logitech is awesome. I love being able to program this many macros (I do game a little, but I find that it works extremely well for programming).
I think that Microsoft has always made good keyboards, and mice too. I have an Hp one, and I'm using this one because it came with the computer that I just recently bought, but I have used Microsoft keyboards in the past and I must say that I have liked them to death!