J line pros and cons:

Pros: just the connections of san pedro and el monte to downtown, and is a crucial line for people commuting to Cal State LA or Dominguez Hills. When moving through the transit way, these busses move FAST cause of their priority: Fastrak acts as a deterrence because most people dont want to pay extra to use a lane. Allowing other busses in is also great, gives it flexibility.

Cons: Busses are too small for the amount of people I see on it. For it being a major metro line, you'd think they'd use double articulated but no, so first thing to fix is capacity. Second is the really goofy section between carson and harbor gateway: it has to exit on Torrance, go up fig street, then pull into harbor gateway. Granted there's no exit going northbound to get to it, but it's still strange. Once it hits DTLA, you're crawling, so the speed is consistent: noy rrally anything to fix this. The stations along the 110 are really noisy and can use better soundproofing.

Overall pretty good for what it is, could be better.