I agree with lane splitting in preference to passing on the right because of glass, doo-doo and whatever along the curb. That's also where you're most likely to get a passenger deciding to open a door and hop out and walk the half block to their destination rather than continue to wait...but it's not the only place this happens. When you're filtering in stopped traffic, any door can pop open at any time, so filter sloooowly and be ready for it.