[merckx56]

The chains are virtually indentical. The weights are identical. I know US pro wrenches that use Ultegra chains because they are less expensive and the work exactly the same.

I ride Ultegra or D/A, depending on what is laying around. The difference at cost is less than $5. Rock the Ultegra. You'll never know the difference.

As for cassettes, I only ride Ultegra. They are WAY cheaper and actually last longer, since they are steel.