different versions of the Sandisk 4GB Memory Stick duo

What the hell are the differences among these three memory stick pro duos and the transparent red 4GB one which are all made by Sandisk?

http://www.jr.com/JRSectionView.process?Ntt=sandisk+memory+stick+pro+duo+4gb&Nty=1&Me=3014305&D=sandisk+memory+stick+pro+duo+4gb&Ntx=mode+matchall&N=24305&Ntk=All_Record_Search&Ne=0

[crait]

they are different, because of thier speed
some you can access memory faster then older, obsolete ones

also the model sets them apart, just like cloth stores, Sandisc releases newer, cooler looking, lighter versions

But all of the ones I listed should basically work just fine with perhaps slightly different read write times right?

[crait]

But all of the ones I listed should basically work just fine with perhaps slightly different read write times right?

exactly