Post ID At The End Of Permalink URL Effects Performance (Positively)?

Question

HARD NOTE: This question is solely about performance, and NOT search engine optimization. So, please make sure your answers are as such.

W.r.t permalinks, "year" is the most obvious numeric of choice, and nothing can be more specific to a post than a post ID (also a numeric).

1. Otto has for so long been suggesting the use of a permalink structure that "starts with something easily identifiable, like a number."

   => something like this (since he said at the "start"): http://example.com/2012/post-name/

2. But from a discussion in WP.SE chat, I've learnt that the WP_Query system parses its request (a post permalink information) "from right to left."

   => something like this should perform better: http://example.com/post-name/121/

   (where, 121 is the post ID)

QUESTION: To me, points (1) and (2) are contradictory. Which one is true? Am I missing something here?

I sure do know that some fixes in WordPress 3.3.X have shown "huge performance gains" for permalink structures independent of a numeric, BUT that does not necessarily mean, there's NO performance loss (even the slightest). So IMO, this question is not completely irrelevant.