Yes, the Agility has the same Indilinx Barefoot controller chip, but uses cheaper (usually slower) flash chips than the Vertex.

I also seem to recall that it has only half the channels (bandwidth) to/from the controller, but I cannot find where I thought I once read that. EDIT: Oh, perhaps something in this rather confusing thread.

In practice, The Agility normally performs so close to the Vertex that there's just no point in paying more for a Vertex now. Or at at least that's true for a SATA1 interface like the one in my notebook here.

And gotta love the pricing on the Intel G2 SSDs, too. Things are excellent in this space, and still getting even better very quickly!

Cheers