Peter,
The reason for the thread was based on a few factors I read here.
http://www.taunton.com/finecooking/pages/c00053.aspI saw pro's and cons for both, in the end, you have to control the yeast and let the bacteria do it's job as well. That's the way I read it anyway.
The last sub-heading is what captured my attention. It reads as follows.
Yeast has help in producing flavorful compounds. Bacteria are important flavor builders as well. There are bacteria in the dough from the beginning, but as long as the yeast is very active, it consumes sugars as quickly as they're produced, leaving no food for the bacteria, which also like sugar. But when bakers chill a dough and slow down its rise, the cold dramatically reduces yeast activity. The bacteria, on the other hand, function well even in cold temperatures, so they now have an opportunity to thrive, producing many more marvelously flavorful acids.
The pro's the way I see it is this;
1. Give the poolish the gluten and malt to feed the yeast - the amount of yeast used is critical over the time you want it to ferment, hence, the bacterial activity - or lack of it - is subjected to your fermentation time.
Varasano,
I see merit in flour and water only too - it seems that your method suggests bacterial growth initially - then spiked with yeast in the final dough formulation.
PS - I enjoyed the good read at your site. Send me some Patsy preferment

Either way, I thought it would be of interest for members to discuss it.
Loch,
I am from hard knocks too, but have no background knowledge of baking like you have.
This is what I have tried.
I added just under 1% of Dry Diastatic Malt (Dark) to the poolish - and later added just over 2% of Vital Wheat Gluten to the final dough. The pizza turned out to be my second best - so the fans say (the kids), they are the harshest critics lol. Too many variables to discuss my harsh experiment, though, I am starting to quantify it for personal interest. What got me moving was that I started thinking that the Vital Wheat Gluten should of been added first in the poolish and then add the missing sugars in the final dough to help with browning. Now here is the sticky point with me - the bacteria need to feed off sugar too. Hmmmmmmmmm.
Enjoying the Journey,
Wazza McG
PS - I know it's not bread, just appreciating similar principles!