Which Paypal?

[Fairyglass]

We already accept Paypal on our sites using the basic package, although we have a business account set up with them. I've had a marketing e-mail today from PP announcing a new "product search" for merchants who use Express, so I'm considering upgrading my account.
There seem to be three options- basic (payments), Express and Pro- can anyone clarify why I should consider Pro or Express, apart from the product search? Transaction fees appear the same on all three systems.
I'm sure I'm missing something obvious- someone please enlighten me!
Many thanks
Ben

edit: I just realised Pro includes merchant account (which I already have)- should have read a little more before posting. Why Express over standard though- any reason? /edit

[TraceyG]

Express allows your customer to go direct to Paypal to pay rather than going through the Actinic checkout process - see this thread for a bit more detail.

[Fairyglass]

Thanks Tracey,
I signed with them yesterday, seems like a better checkout than "standard" PP.