Who Should Cut My Hair?

I´m thinking about cutting my hair... but I´m not sure if I should go to my usual hairdresser or try with a new one.

I have a lot of hair and it's not easy to cut it, but lately my hairdresser has not get the exact haircut I desired. She understands my style and at the end the cut is OK... but... should I try with a new one?

The new one cut my sis's hair quite well last time. For that reason I´m thinking about changing.

I have two weeks to think about it but it's not an easy decision.

What would you do if you were I?