Stix,
Thanks your reply.I assume a duet is the NSW version of the any 2,and no,I wouldn't touch either with a barge pole.If your approach with exactas works for you stick with it.My angle is similar to yours,I look for at least one standout(IMO)at each of the major meetings.If nothing "jumps out and picks itself"I go thru each state and concentrate on the race with the shortest PP fav.Then I run the fav thru a strict selection criteria and if it qualifies it becomes the banker.I then price it coupled with the next 5 in the PP market and bet each state to win a $100(plus my stake).I don't bet in fields greater than 11,as the percentages start working against you.I prefer quinellas to exactas because you have the added insurance that if your "good thing"gets nutted on the post,you could still get the quin.If you get nutted in an exacta,your money is down the gurgler.
The thing with quinellas that the majority of punters don't savvy is that the real value lies in the shorter priced combos.If you do your homework and bet to prices you will get approx. 80% overlays in the evens / 10/1 range.This is because the average punter will see a short priced fav and take it with the field hoping for a bolter to come 2nd.
Here are some expected divvies with bolters........

6/4 /20/1..............18/1
6/4.../25/1............23/1
6/4../50/1.............47/1
6/4../100/1............93/1

As the figures show there is very little value in taking the field with a short price fav.
My method is to cover the next 5 in the pp market to win $100,then cover my ******** with the roughies for the same result at very minimal extra cost.
Remember the first 5 horses in the PP win approx. 80% of all races,so the figures are with you.And at the shorter end of the scale a quin you priced @$3.80 can and does often pay $5 and up,because the small punters won't take it,leaving the pool to be plundered.
Hope I haven't bored you too much.
cheers