My biggest issue is the time it takes to get a call answered. Sometimes its real quick (good), othertimes you can be waiting up to 20 minutes. The long wait times do not happen as frequently as it once did. So I think things are improving in this area.
Consequently I avoid calling when I can.
Once I get hold of an actual person its usually pretty good.
If you get an issue that needs to get deferred to development then you sometimes stop getting any updates. I find this frustrating.
Sometimes on a longer running case I get support engineers asking me for the same things that have already been supplied. That is also frustrating.
On the whole, I think things have been improving.
The problem with humans is we tend to remember the bad experiences we have and treat them with a greater weight than all the good experiences. Also you don't usually call support because your are having a great time to ask how their day is going. You are usually under duress and pressure, and this makes things that would otherwise be a small issue seem much worse.