I have been using ESO since launch and have had intermittent problems with patches, which are made worse by having a slow'ish internet speed where I live.
This week the 1.10 patch is making me download 24GB as other people have noted. I of course would like to know why?
I always work with around 25 - 30GB of spare space on my HDD and I was unable to start the download of the patch until I freed up 50GB of space.... to do this I had to delete a 19GB game!!

Now the patch is downloading and it is taking a loooooooooong time. Longer than 24GB would normally take.
..... and apparently the patch is only 450MB.
So between Sony & Zenimax.... WHAT THE HELL IS GOING ON?