They are still very variable for me (UK). With Royal Mail etc., I can be all but certain that by about 2pm I'll have the package. Most of the time, Amazon can match that, but I definitely get more issues with them than with other carriers (deliveries as late as 10pm, missed deliveries, items arriving damaged, items left in weird places [e.g. wheelie bin shortly before it was due to be emptied] even when people are in the house, items left in "safe" places without leaving any notification, misleading email notifications etc.). They've definitely improved, but are still a lesser service in my experience.

I avoid all the 'carriers' and use the Local Collect to my local Post Office. Only disadvantage I guess is the Sunday deliveries, but It's a worth while trade-off.

Same experience here in the UK. Started out poor, but now just as good as Royal Mail.