Very interesting fantasyfan; thanks. I'm still leaning towards the Dawood mostly because I want to give a go at reading some entire edition and that seems the most well-rounded so far without being too long. Since the Lane is free and you recommend it so highly I'll probably download and read parts of it too, especially for the annotations.
For anyone who didn't read the vote thread, I made
this post concerning possible versions (fantasyfan also made
this post there but he's already eloquently posted his information above).
Haddawy seems a very good option too, but it's in two volumes that total around 700-800 pages. Apparently, he is very critical in the first volume's introduction of versions that aren't from the 'correct' sources that he uses and since he followed those particular sources so fervently he left out some of the most popular and well-known stories, which is why there is a second volume, as at some point he decided to (or else his publishers convinced him to) include those well-known stories left out from the first volume in a shorter, second one.
I haven't found much info on what Mack's version is like yet. From looking at its Amazon page, I do see it's longer (at around 1,000 pages) than both volumes of Haddawy combined, but I do like Oxford editions. I see that it is the earliest English translation (from a French translation) and not a newer one, but it does have extensive notes and criticism.