USB vs. RS-232 for an Ohaus SP6000 Scale

I am attempting to connect to this scale: http://balance.balances.com/scales/272/

However, I need to purchase an USB or RS-232 connector in order to retrieve data.

http://scaleman.com/ohaus-71147377-usb-scout-pro-interface.html

http://scaleman.com/ohaus-71147376-rs232-scale-interface.html

How much will the connection difference change the way the VI operates?  Is there a preferred method between RS-232 and USB?

I want to create a VI to determine when the scale has reached steady state, store the scale data, repeat, and then compile the data into an array to export to a spreadsheet.

Thanks!