Thanks for the advice guys. I'm still really undecided.
I am aware of the 25nm issue but I'm really struggling to decide if the price reduction is worth the loss in performance.
The reality is that in a few weeks or couple months the 34nm SSDs will not be on the market. So I doubt the lifespan and error issues has not been properly accounted for by the extra over-provisioning. However, I don't like the idea of loss in performance.
I've seen tests using incompressible data show the new 25nm SSDs (the ones with 64Gb ICs) performing way worse than the 34nm ones, but the "real world" tests (which use a lot of compressible data) show they perform on par.
OCZ has an SSD (in the following link) that could be either 25/34nm but uses 32Gb ICs instead of 34Gb which supposedly keeps the performance the same as the old 34nm.
NCIX.com - Buy OCZ Vertex 2 Extended Sandforce New 16 Chip Solution 120GB 2.5IN SATA2 Solid State Disk Flash Drive - OCZ Technology - OCZSSD2-2VTX120G - in Canada
So it might be better for me to get that one. It's $225 so it's like $60 more than the one I linked in my first post. Maybe that one will become cheaper once 25nm matures more, though I understand it will still be more expensive than the 25nm ones using 64Gb ICs.
This is not going to be easy for me to decide.