depending on when you buy it, it may have 5.1 by then. anyways, you can't downgrade 5.xx at the moment, i believe devteam is working on this with their next tool.
shsh blobs are a thing of a past, meaning they don't work with 5.xx.
Ah right. I heard that it was possible to downgrade the wifi only models (which is what I'm getting), untethered at least. Is there any truth to this?