Siri couldn't figure out how to adjust my Nest's temperature, not very powerful. I expect things to "just work".
One of my annoyances about the new Hey Siri feature is that it tries to be too cute and flippant. I asked early in the morning what the time was as I didn't want to open my eyes and it replied "It's 5:30 am, too early to wake up I'll say".
Just tell me the time, forget about the colorful dialog to go with it, especially at 5:30 in the morning.
Another time when I first got it, I asked Siri something and of course the display goes on with the answer on screen along with the vocal response, but it was night and I tried to see if I could turn off the display quickly, so I said "Hey Siri, go to sleep". It replied "Siri never sleeps".
But when I asked the next morning for the time, it said "It's 7:28 am, you woke me up". When I asked "Hey Siri, I thought you never went to sleep", it didn't respond.
I also noticed Siri set up about 12 alarms for the same time because I kept asking it to "set" my 8:00 am alarm instead of "turn on" my 8:00 am alarm. Why would any supposedly powerful OS think I wanted 12 alarms set for the same exact time?
As you can see except for telling time I haven't really found any use for asking your iPad to do anything hands free especially when it must be plugged in to use it that way. So all that changed is nothing really except a mildly annoying feature not very well implemented, again.