I'd be careful on BUR. Assuming you're on UA, it will most likely mean connecting through SFO. United Express is notorious for cancelling Skywest operated flights when SFO has weather delays - BUR is a prime candidate for it.

On top of that, SFO is closing the "1s" this summer through September. That will reduce throughput even further.

Plus, you normally depart out of T1 on Skywest which makes a Greyhound bus terminal seem posh and requires a transfer bus.

So, I would avoid BUR to be honest right now. LAX or ONT would be my recommendations.