We've done several hop-on/hop-off tours in other cities that we've enjoyed, but LA may not be suited well for it with its traffic and long distances between stops. We waited 20 mins longer than the expected arrival terminal to hop on our first time due to delayed buses caused by traffic. As well, the stops throughout the city are not marked at all and you need to rely on the Big Bus app to ensure you are at the right place, as the bus barely waits a minute if they don't see anyone looking to board. It sounds as though Big Bus is relatively new to LA (Since March according to our guides), and their frequency is pretty low at 30 mins between buses, unless bus breakdowns make it even longer - which happened on our day with their blue route to Santa Monica where some other guests were waiting up to an hour. In other cities we usually only had to wait 15-20 mins at most between buses. This makes it hard to visit attractions at most stops as you want to make sure you catch the next bus and 30 mins may not be enough time, and you don't want to risk waiting for an hour. We saw buses from other companies go by more frequently.
Once on board, the guides were generally good as they interacted with the passengers and told stories about the places we drove by. Jacob was particularly good at keeping us entertained as we sat through a particularly long stretch between stops due to traffic caused by construction.
We were recommended not to take the blue route on a Friday afternoon, as the ride back from the beach would take far too long in heavy traffic. It was good advice, so we just did the red route, but it made the overall tour price not worth it.
Having been on the tour now, I wouldn't do it again - the main attractions are too far apart and it's much faster to Uber or drive yourself to the attractions you really want to see without driving across town through traffic. It's not practical to walk between most stops as they are not close enough to each other, so you end up being tied to the bus frequency.