I just wanted to add that I agree that education about BF makes a massive difference.
I BF my daughter for just shy of 3 months. Struggling through that growht spurt, I gave one bottle of formula to her, and she flat refused to latch on to me ever again (I was devastated). She would scream and scream when I tried to feed her. After that experience, I set about educating myself (with lots of help from this site).
This time, my son has had formula for two days on two seperate occasions due to medical complications. The 1st two day period started at 36 hours, my milk wasn't in yet, I was instructed to pump, and we added what colustrum I pumped into the formula he was being tube fed.
The second two day period started at 9 days old - due to a rare complication, formula was actually better for him in the short term than my breast milk. I insisted on tube feeding, no bottles (still pretty upset about the issue with my daughter

). Paed was absolutely fine with this, said it was my choice. I did have one midwife come in and say - why are we tube feeding if you are giving him formula - and I instantly explained. She apologised, said she had just come on shift and hadn't had a chance to read our notes yet.
The thing with all of this is - if I didn't know how difficult it can be to get things working properly with BF, and hadn't educated myself about it all, I would have allowed the bottle feeding - and maybe that would have affected BF establishment, and maybe it wouldn't - but without the knowledge, it wouldn't really have been a concious choice iykwim. A friend also had to formula feed her baby early on, and pump, same as I did - she is not as educated about BF (nor as determined to do it I don't think), and her baby got bottle fed.
I am not anti formula, but this early on in the BF process, I am anti bottle, only because of how things went with my daughter.