Really? I've been putting additional conditions on a left join for 20 years now. Its a second nature to me. You can do really beautiful things with it which you cannot achieve as easily in any other way.

Right, some do it regularly and others prefer to use the JOIN only for keys. I've seen plenty of good developers who use either approach. There's never been an absolute standard, so you'll always have developers coming at it from different angles....some approaches better, some worse, and some different-but-equivalent.

With a covering index to include the TotalDue, the execution plans are identical.