Mira mesa has a huge rental demand working for it. With UCSD expanding, it’s the closest area where students can afford a 4 bdrm house and live with all of their friends. Not to mention, its lower price caters to all of the blue color jobs on Miramar as well as the military base. The houses are old and neighborhood is run down, but its got a pretty desirable central location which helps.
That said, the layout of MM sucks, MM blvd gets congested easily and there’s a limited number of alternate routes.
The railroad crossing only gets bad if a train happens to go by between 4:30-5:30. That’s when all of the folks leaving work from Sorrento valley get bottled up at that intersection trying to get to the 5. An ill timed train throws a huge monkey wrench into an already poorly running machine.