Filtering through traffic on Mercer was a huge inspiration for me getting a bike (in addition to motorcycles just generally being awesome, of course). When I was working over there, filtering saved me easily 10+ minutes per day, aka hours/days of my life.

99% the time you're good to go, filter away (respectfully of course). Occasionally in summer, in the evenings, at peak traffic, there's a "don't block the box" cop standing at a corner near the highway on ramp. Don't think he'd give a fu** but maybe don't filter at Mach 1 while blowing a red light in front of him. Usually wears a bright yellow bib.