Well, I'm not sure if it's just me and what Echo has gotten used to, or if this works for everyone, or if this is something obvious everyone has always known, but I discovered a few days ago that I don't have to say "Alexa" and just "Lexa" works fine (and actually more reliably) on all three of my devices.
Not a huge deal, but it's a bit easier (one less syllable) and, like I say, I find it a bit more reliable (she seems to understand me better). Anyone else find this out?