Dell Mini Atom processors-front side bus 533mhz and 667mhz difference?

I am looking at buying a Dell mini 10v, and I am thinking about getting the n280 instead of the n270. The n270 is 1.6ghz with a 533mhz fsb, and the n280 is 1.66 ghz with a 667mhz fsb. Both have a 512k cache. How much of a difference will I notice with the upgrade?