Alexa is my sister's name and I love it. We have only met three others since she was born (which was over 20 years ago, she's older than me) and she has always been the only one with the name in school/dance class etc. I think it's strong, pretty and not overused. Not nearly as common as
Alexis and
Alexandra. I really like it.
I don't like
Alastair. It's not horrible, but it sounds a bit conceited and unattractive. I prefer
Alistair over
Alastair.
Keep
Alexa, lose
Alastair,
Alistair.