I have Wolfhounds. There are too many pros to list. (I'm a tad biased)

The only true con is their short lifespan, although my oldest girl, Mouse, will
be 9 years old in March. All the other stuff like needing bigger everything, larger
vet and food bills etc. are just part of owning a giant breed.
If you are seriously considering a Wolfhound, I strongly recommend the book
The Magnificent Irish Wolfhound by Mary McBryde. It's a bit pricey, but worth
every penny. Or perhaps your library will have it.
For fun, I asked my family and a some close friends to give me one word to
describe wolfhounds. (my three)
Calm
Patient
Loyal
Gentle
Awesome
Super dignified
Very intelligent
Sensitive
And from me: they make me smile/laugh every day.