not too sure about scan
use them a lot and no problems with them
but have seen them rate some things with less than 3 out of 3 stars that were excellent items
i like sites like aria.co.uk where users review and rate the hardware--their staff will also answer any questions you have
i also use and have had no problems with ebuyer,dabs,novatech,overclockers.co.uk,tekheads
what makes a good case?
airflow,how loud,cable management,build quality,looks--though that ones subjective to what taste you have