My experience of check-in and security lines at LAX is a month old, so
others will have more recent information, I'm sure, but when we were transitting,
the check-in queues were long, long, long. We were fortunate in having
a magic card that allowed us to circumvent them and were quietly congratulating
ourselves until we found that there was no way of avoiding going back
to the street entry after check-in, which was the starting point for the
security lines. Not long after we had joined the lines - of very grumpy
people - the starting point had extended out the doors.
It took us almost two hours to pass through security - including my fourth
body search for that trip (New Orleans/Denver/LAX). There were more people
on crowd control than there were on the security checks themselves, which
seemed the wrong way around, but from what I have been reading from Ziners,
the systems may have improved by now.
The seating problems on our flight were more chaotic than anything I have
ever seen - and that is over many years of round the world flights! Chatting
to the cabin crew later, we discovered that the problems were the result
of many people missing two earlier flights and having to be accommodated
on our flight - which in turn was possible because of the number who missed
our flight. And you guessed it, mainly because of the security lines!
So, my advice would be not to risk missing your flight. Get through security
and find a good book and a comfortable lounge, if you have any means of
access to a Club lounge of any sort.
Best of luck,