I think most posties do a really good job in our area, mind you some might say I would say that given it's what Mr.J was before he retired at the beginning of December lol When we go to Tesco we're constantly stopped by his old customers saying how much he's missed.
Regarding incorrect postage, I'm reliably informed that the postie doesn't actually get given these items, they're pulled out at the sorting stage. Instead they received the appropriate card advising collection which they have to deliver along with their other post so sadly there's no opportunity for them to use discretion.
Since the new working practices were introduced about 15mths ago the job has become much tougher, many more packages which won't go through even a good sized letter box, even car tyres would you believe Mr.J has seen a big downturn in morale and tbh he wasn't sorry to leave.