Dave,
By definition, intermediates, are supposed to be roughly the same density as the water, despite the fact that the companies like to assign them a sink rate, usually 1.5" per second.
I have a full sink and the intermediate, and find I use the intermediate probably 75% of the time.
PS I just got the GL3 Mega 10/11, but haven't cast it yet. Seems wicked nice though. Let me know if you want to check it out.
Jay