DDR2 for £100 or under? (2Gb)

[SideWinder]

Basically, is there any real performance difference between PC2 8500+ and all the way down to PC2 4200?

Looking for DDR2 to go in a Shuttle, aiming for 2Gb.

Comments?

 

[SideWinder]

Apparently that's how they are packaged? (G-Skill)