My first cocker (1970's) was docked, as all cockers were then, and it didn't diminish his joie de vivre. Sophie (2000) was undocked, with something of a corkscrew because, I think, one of her littermates had chewed it! Even so she carried it with great pride. When she was very ill with meningitis her tail was her main way to communicate.
When we got Annie from Many Tears I wasn't sure if she hadn't been docked. It turned out that her tail was so tightly folded under her that it was nearly invisible. It was wonderful when it emerged and the flag started to fly.
I understand and support docking dogs who are going to work in the field, because of the seriousness of the injuries they can sustain, even if they are rare. For a pet however, I wouldn't contemplate docking.
There is something very reassuring about the exchange that goes:
'How you doing Annie?'
'Thump, thump, thump...'