I just checked my figures (pre-commission let me stress) for those 134 bets

If laying to $5 level stakes +247
If laying to $10 liability +329

Today there were 11 races with 7 winning lays
$5 level +2.51 (only +$0.23 after commission)
$10 liability +9.76 (+$6.52 after commission)

I still don't believe I am comparing apples with apples so I suppose it's just a matter of which side of $2.50 the winners/losers fall for which way would be best.

__________________
Never give up on a dream just because of the time it will take to accomplish it. The time will pass anyway.”

― Earl Nightingale