From some reading online, I have found that seed banks are often stuffed with low quality seeds, which may not germinate, and probably will not be adapted to the local area. Some unscrupulous venders figure that the seeds will never actually be planted; they will just be stuck on a shelf.
However, there seems to be variation among seed banks; some are better, others worse.
Has anyone actually used the seed in the vault sold by Heirloom Organics? Their website is www.heirloom-organics.com.