For the record - I live on Dartmouth Road and seem to get a very good service (certainly in comparison to other postings). The post is pretty much always delivered by the same postman, and at around the same time (circa 1pm).

In addition, I have never had an issue with either (a) lost post, or (b) overly slow post.

Perhaps the service on Devonshire road is coming from a different office (unlikely, but I guess could be possible)?