I think that, all things being equal (no problems with bf):
- in the early days, breastfeeding is harder, because it's more time-consuming, but it's easier, because you can use it to comfort a newborn more easily than a bottle or paci
- after 3 months (give or take a little), breastfeeding is MUCH easier in the daytime, because you can go anywhere, not pack much, not look for water fountains or bring a cooler, etc.
- at nighttime, formula feeding is hands-down easier. Because someone else can do it for you. :-P
Add pumping to the equation, and bf is much harder than FF. You do twice as much work and clean just as many bottles.
FWIW, when DS was younger and needed to eat at night, we had to FF in addition to BF at night (my supply is crappy). We had a simple routine; we never sterilized or washed bottles at night (hello, dishwasher?), we never went down to the kitchen or measured powder. We put several bottles with pre-measured water on the nightstand, had a container for pre-measured formula powder, and just dumped the powder in one quick motion into the water, capped, and shook. The "FFing is soooo much work" argument dates back to an era when moms were still told to sterilize bottles before using them, every time.
Now that DS is 18 mos, we rarely give bottles at night, and he just comfort nurses back to sleep. And dude, there are quite a few nights that I am awake for the fourth time, staring over at my slumbering DH, and missing the days when we took turns giving formula bottles at night!
Breastfeeding for me has been much harder, but also more satisfying.