wouldn't they always go for the one with highest offer? more $$$ for their effort?
I personally went for certainty than the amount when selling - because i needed assurance of paying my committments than making max profit at the time.
This is where you really need to get into the head of the vendor - why they are selling.
Remember as a vendor, the minute you accept a conditional offer, you can not accept any other offers. If the conditional offer bombs, you need to contact anyone who might still be interested, do open for inspections, clean up the yard etc. That could waste you weeks of time, as well as cost you hundreds in interest costs etc.
Back to the topic of the this thread - a full 10% put down with the offer *may* indicate to the vendor you are "cashed up" and aren't going to stuff around with getting finance organised etc etc etc.
Cheers,
The Y-man