My LHS has gotten their Atlas track stock back up to pre-shortage levels, this includes most switches which were really hard to find for a while. As Jan said above, I think the #5's are still in short supply, but supposed to be available soon. The large dealers in the East should have plenty of it by now.
Noise level is a big reason I went with Atlas track. Very quiet. I also really liked the look of it. I am really sold on the solid nickel-silver rails. Sclaetrax is the only other solid nickel-silver 3 rail track that I know of and my LHS does not carry it.