Thanks heaps, Stugots. Looks like I used too small a sample of Saturdays. Yesterday was not flash, either.
I still think Michaelg is onto something here. His main filters (the first four in his last post) put Top Raters into two categories I reckon: Good Value (his selections) and Bad Value (the Top Raters he filters out).
If we can't turn a consistent profit on the Good Values, maybe we can on the Bad Values. For example:
-only Metrop meetings
-only races where only one Top Rater
-only where the Top Rater takes a sizeable percentage of the pool, e.g. win price of $5.00 and below
-Lay on Betfair, or bet around the Top Rater.

I'll do some more work and let you guys know if I find anything that works consistently.