My UPS guy is awesome, stashes my packages around back. It's down to the individual, as to be expected.
In general I find Amazon to be the sloppiest but it's different people. I have noticed a marked difference between the Amazon folks, and yes I can tell by appearance. This is especially true with returns. There are exceptions, but few. The flip side being the tracking updates are almost to the second.
Fedex is pretty uniformly sloppy with deliveries but I don't often see them, they're like ninjas.
DHL and Purolator are almost always the worst. No knock, failed delivery sticker that often ends up in the hedges.
I only get Canpar on occasion, not a big enough sample size to critque.