How long does it take to submit an application via EFS-Web?

The time involved will depend upon the speed of your Internet connection and the size of the PDF files you are submitting. However, filing in EFS-Web has significant time improvements over the previous electronic filing systems. PASAT and ABX took a significant amount of time to transmit complex XML documents over the Internet, unlike EFS-Web which transmits common PDF file attachments to USPTO.

USPTO FAQ - Questions and Answers (15AUG2007)