I personally like the current navbar defaults in general, but this is really a matter of "the eye of the beholder". I don't think I actually used the default in any of the designs of ours. I wouldn't, no matter what the default was, since every page / app is so different.
The welcome app is supposed to be hacked, deleted, obliterated to pieces, etc., so navbar is probably changed / adjusted / customized in one way or another in every single custom design out there. As for js dinamically changing the padding... I really don't see the need. Once it's set properly, it's set. So why running javascript every single time?
Regards,
Ales