Vendor Import/update

We are looking at interfacing Vendor data into PeopleSoft and looking at the three alternatives....

Flat File Import

Excel to CI Import

Integration Broker XML

Based on the amount of Vendors updates and timelyness (Looks like initially 250 vendors with 10-20 updates per month.) of the updates, we are leaning to Excel to CI. 

Does anyone else use this?  Does it allow for updates to existing vendors?  Does it handle effective date logic?  I.e., if target address information exists, can the Excel to CI insert the new effective dated address record while maintaining the old address data?

Thank you,

Richard