Update on these 2:

The snakes I think were suffering from a case of "OMG we've never spent this much on a pair of snakes before" syndrome with a hint of "we've never actually heard what an RI sounds like"-itis.

They still sound funny to my ears when they hiss, but it isn't getting worse, so I am inclined to believe they just don't hiss nearly as enthusiastically as our one other hisser.

So now I'll give them their week to settle in and then I'll get pics up.