Default tar for 1.3 and later

[Hummel Tom]

is there any objection to switch the default tar to BSD tar?
GNU tar will be kept, since some features for tape handling
and updating are missing in BSD tar, but the latter does a
better job for the normal use cases.
Which format is BSD tar using by default, ustar (POSIX.1-1988) or posix 
(POSIX.1-2001)?
What about the reading of V7 and star formats?

I'm trying to collect some information about this topic.

tom