Hi,
Word completion seems to look for matching words on the document from the cursor point and up, and then, from the cursor down. It's often the case, however, that the matching word you need is right on the next line, or even later in the same line, and it takes a lot of ESC-pressing to get to it.
My suggestion is that you sort them by proximity (as it is now), but look for words in both directions, so the words right in the next line stand a better chance.
(I had the impression that back in 1.0 it worked that way. Did it?)