I got Legendary Survivor 4 times now - 2 pre-EoTN doing Jade Brotherhood runs (Monk and Ele), and 2 post-EoTN doing Killroy runs (Monk and Asn).
There's no doubt that Killroy is the best method. I'd prefer to fail at 7:00 hours of gameplay by lagging at Killroy than fail at 70:00 hours playing normally. By that time, I could have tried around 10 times again on Killroy and maybe gotten the title.
I recommend to farm for the title, yes, because 1.337 M EXP is A LOT to get normally without doing something stupid or disconnecting. Capping skills is an option, but is expensive - use that money buying scrolls to do Killroy, it gets the title faster and safer than capping.
Cut the times of Killroy runs as much as possible by using the best scrolls you can afford - less runs, less risk.
Best of luck.