Just returned from 2010 trek. Saw only one bear, not a threat. No incidents with our crew/gear.
Rangers and staff at PSR are very strict regarding bear precautions. Whilst the provided ropes are not perhaps the best, they work more than adequately using the prescribed procedures. Lighter ropes may save a few ounces, but unless you're carrying much stuff that's not needed, the rope weights won't be a significant issue.
We did hear of several bear incidents, but I cannot report with confidence on the credibility of the reports. Widely variant reports on same incidents cropped up repeatedly.
My recommendation is to follow PSR procedures for hanging smellables, and use their gear. Effective, and the staff are comfortable with their procedures. Small gains in using non-prescribed methods/gear don't outweigh cost and time involved in arguing with staff.