The part that runs on Market Street is the useful part. The part that runs along the Embarcadero isn’t useless, but it’s more seasonally useful. I’d rather see the old PCC cars replaced with a solid modern low-floor LRV using more standardized parts & aggressive transit policing to keep freeloaders from abusing the system. It is partially redundant with the subway, but if you’re going to have a surface street railway anyway, I’d rather it be optimized for local use.

You could pull the J up from underground too using the same low-floor LRV model chosen for the new F, having it turn at Church & Market rather than making an awkward diversion to Church & Duboce first.