I breastfed my daughter for 28 months without a drop of formula (just recently weaned a couple days ago). It gets lonely, and you're the only one who can feed them night and day.
BUT you get so much more sleep, it's easier and faster, and no bottles when you go out! Just diapers!
My son, however, had a tongue and lip tie cut and couldn't Breastfeed AT ALL at 2 months old. I was suddenly thrown into the world of bottles... Something I've never done.
Washing bottles suck. Your baby is breastfed, so chances are, until baby is used to a bottle routine, baby will drink way more than 5/6 bottles a day (my son drank 20 the first couple days-- I was super exhausted, and even at 3 weeks of bottles, he takes 10 - 15 bottles (anywhere from a half f an ounce to 3oz).
Sterilizing, paying money on formula, changing formula if it doesn't work with your baby, finding the right bottles, etc.
Your hormones get a bit crazy as your milk dries...
HOWEVER, I do enjoy knowin exactly how much he eats, that others can feed him, and that his feeds are way more spaced out than his or his sisters have ever been (she fed every 1.5 hours until she was 14 or 16ish months?) and he fed every 45 minutes.
Both have pros and cons, it's just up to the individual.
(Oh, and if I had a choice, I would bottle feed breastmilk lol nice in between).