Comparing shops fairly
Two quotes are only useful if they cover the same work.
Ask for the same details
Ask each shop for the labor hours, the hourly rate, the part brand and type, and the warranty. Then compare like with like.
Dealer vs. independent
Dealers often know one brand deeply and use OEM parts but may charge more per hour. Independent shops can be cheaper and very skilled; look for technicians with ASE certification.
Reviews and reputation
Read several recent reviews and look for patterns, like many complaints about surprise charges, rather than judging on one review.