StartRoutine in TransferStructure or Updaterule ??

Hi all,

where is the best way to change incoming data from R/3?

background: we often have loadprob's with orders + deliveries concerning incorrect datefields (not in calendar or misstyped) and therefor we will check them in a startroutine and replace incorrect with current date. question is: better in transferstructures or updaterules startroutine ? what is the best solution.

thx for your help

/manfred