bzr+ssh:// vs. bzr:// vs. sftp://

[Tzury Bar Yochay]

I could not find a summery page that explain the differences between
these different schemes.

I assume (correct me if I am wrong) that sftp / ssh are the same in
the aspect of security.

What I would love to know is:
    1. Is using bzr+ssh:// faster than sftp:// ?
    2. Is using bzr:// alone will make the whole packs transfered as
clear text?

(( The current buzz around Bazaar tempting me to call it Buzzar ;-) ))