I evaluated a Sig DAO for my former agency when they first came out maybe 8 years ago. My personal opinion was that they had truly turned a silk purse into a sow’s ear.
The heavy trigger pull was bad, but even worse for me was the weak trigger return spring combined with the true DA mechanism (unlike, say, a Glock where the mechanism is actually partially cocked). I found I had to deliberately move my trigger finger forward after firing a round to allow the trigger to fully reset.
Sig has since redesigned both the mainspring and the trigger return spring, so it’s probably not as bad as it used to be.
OTHO, I ran the range where I used to work and I occasionally saw employees start to holster cocked (and loaded!) Sigs, so I certainly can see the advantage of DAO!!
Frankly, while I think Sigs are fantastic SA/DA pistols, there are IMHO far better so-called DAO pistols out there.