Yes horses with pre-post divs of $11 (or $13) or less do dominate the winners circle. That's because these odds are posted by bookies when they frame a market for the w/e. Their assessments for the w/e are usually a better guide than punters who distort the odds on saturday.

Often winning horses will have pre-post odds of $5-$8, but drift out. These markets may be framed at 140%+, so that explains the drift. However, horses in the top half dozen or so in pre-post markets win a lot of races.

I would reckon that the top 6 pre-post favs have a better winning record (and better SP) than top 6 favs on the TAB just before the race.