We decided to ff from birth. Well, it might have developed into mixed feeding - I was prepared to give bf a go for the first few days, especially for the colostrum, and see how I felt about it, but I didn't have a strong feeling towards it. In the end DD was in NICU and we just went onto formula straight away.
Our decision was quite heavily based on my concerns about managing on my own with a tiny baby. DP worked very long shifts and there was no family support on the doorstep. I instinctively felt that if I wasn't in a position for someone else (DP, family) to look after and feed the baby for a few hours, for DP to help with the nightfeeds when he was around, then I would seriously struggle. I still feel this was the right decision for us. I honestly believe if DP would have been home every day at 6, had been home every weekend, or if I'd had family who could simply pop around for an hour, I would have considered bf more and given it more of a go. I guess that depends on how you feel about other people feeding the baby. Personally I enjoyed watching other people feed my baby and enjoying that time with them, and without criticising anyone, I don't quite understand why the thought of anyone else feeding your baby is a bad thing.
I never found making bottles a faff, it just became part of the daily routine and was very easy to do. Nightfeeds weren't an issue at all. Even if I had bf I still wouldn't have co-slept and would still have left the room to feed, because of sharing a bed with a randomly-sleeping shift worker.
I used to feel bad about this decision (well, on MN, not particularly in RL) but not any more. It was the right decision for us as a family. Of course bf is best for the baby if it works out well, and there should be more support there for people who want to do it - for example, for mums with concerns like mine before having the baby, there could be a lot more talk about mixed feeding which I probably would have considered if I had any idea that mixed feeding was a viable possibility. But I was only ever told bf or ff, not that the two can be combined. But at the end of the day it is the mum's choice, and I strongly believe no one should ever feel criticised or commented on or feel they need to defend their choices, whether they are ff'ing or bf'ing until 4yo.