I don't know about OCZ Vertex, but I remember that Intel bragged that its MLC drives can last for about 5 years even if you write a couple of GBs every day.
We are writing quite a lot more than 10GB per SSD per day on ours, and we have run into lifecycle issues. Of course, we are running a lot of these SSD's and striping across them with OS level raid, so we are doing a lot of write IO.
