I am 3 years on from the point where I left him, after escalating EA over a 4 year period and occasional 'red flag' behaviour before that (we've been together 16 years in total, married for 12, one DS aged 6 years). I had exactly the same dilemma and, with pressure from my parents to give it another go, I allowed him a second chance.
He has genuinely worked hard to change, has sought out and engaged with long term therapy to address his issues regarding his father (who's death was one of the triggers for his escalation). I have not seen 'nasty husband' in all that time, he is considerate, loving and affectionate, pulls his weight in the house and engages with DS, frankly, better than I do these days. He fully admits to what he did and how it was wrong, he will discuss it with me whenever I need to. He has supported my career development and outside interests. He ticks all the boxes in Lundy Bancroft's book regarding 'recovery' (and yes I know how very rare that is). You could not wish for a more supportive partner.
And yet. Some things cannot be unsaid or undone. Once I finally relaxed around him I had something of a breakdown. I have had extensive therapy myself to deal with the trauma and the effect on my self confidence of his previous behaviour. And although the love for him has returned, the trust hasn't, at least not completely. And also I don't respect him like I used to and occasionally still feel overwhelmingly angry for what he did to me, but don't feel I can really express that anymore, as I don't want to keep hurting him by raking over old dirt. And that is eating away at me over time. He made some comment the other day about how wonderful it is to be in a relationship where you know that when the chips are down, the other person completely has your back, and I just thought 'yes, but I don't have that.'
I haven't left, but I still have one foot out of the door so to speak. I maintain a savings account in my name only (all other finance has always been joint) and I often fantasise about having my own little place. He would be gutted to hear that, for him it's very much a period in our lives that is over and he is a different person now, but I don't seem to be able to let go and I fear that despite everything I may yet end up leaving him, and it would be much harder now for DS, as he is older and much more involved with his dad than if I'd left 3 years ago when he essentially had no relationship with him.
Sorry about the epic post, I don't know if it'll help, but be aware that he is not the only one who needs to change and recover, whether you stay or not you have a long road ahead for yourself, to heal from the abuse, learn to trust your instincts again, establish your own boundaries and learn what constitutes a good relationship, and that may be much harder for you with him there, even if it's practically and socially easier to remain in the relationship.