if the HD supports SMART, it's good to post the results of that..
Then transfer rates though HDtach are good.
normally when I look for HDs in the FS/t section I go by
manufacturer
mfg Date (for warranty)
Drive model #
revision/firmware
some people are picky though and want the health status of drives, that way they don't pick it up, it dies 2 months later.. then you have lost data, and the hassle of an RMA