I have never run HO cars on a track with copper tape, I have run them on routed tracks with both Magnabraid and tinned copper braid. If you run modern high downforce cars on regular track with rails if the pickup shoes are not properly adjusted to start with they will quickly wear in. On a taped or braided track you need to be more careful about adjusting the shoes. The braided tracks that I have run on were all ovals, two of them had steep banking and one of those had Magnabraid. We ran inline magnet cars on that one, you had to be careful getting on the power as you exited the turns or your car would swap ends. We only ran pancake cars on the high banked track with copper braid. The pickup shoes tended to burn if you did not increase the shoe spring tension and pay special attention to how the shoes were adjusted. The copper braided track with only a slight bank was not as much of a problem, we only run pancake cars on that one. Back in the mid '60s I had some Marx track, which had brass rails, no downforce there!