Is it worth me upgrading to an Intuos?

[Burl]

Hey, I've owned a Graphire 4 for some years now but it's pretty knackered. Since it's always worked well enough for me I've never considered getting a more expensive Intuos, but I think that time has come. I am just wondering if there's a big difference between the two? I think for me it mostly comes down to 512 vs 1024 pressure sensitivity, and if that difference really improves line quality and ease of use.