All the SSD I have tested include extra NAND chips for overprovisioning and/or redundancy. Dont think short stroking is necessary, in fact I would advise against it as you would then be concentrating writes on a smaller portion of the drive. So will hit dead cells faster than using the full drive. 10% does not seem like much
also windows updates in win7 unless they fixed it recenetly exponentially increases OS size on drive.
After a couple of months of use windows 7 with updates will hit about 40GB. that is 30GB of winsxs folder.
Slipstream all updates before installing to help keep this to a minimum