From my experience most mums are happy for good dads to have as much contact as they and the children would like, just not if it is all on the dad's terms. Last minute arrangements and cancellations mean the mum can't make any plans for herself and the children get let down regularly. Consistency and reliability are just as important as regularity.
I've met 2 men who are 50/50 and plenty of others who spend at least one night a week with their DCs. My ex has ours once a week, he was pretty crap as a dad when he lived with us, but since leaving has stepped up and can cope with his one night.
If he wanted 2 nights or even 3 I'd be more than happy, although it would mean him giving me less money than the minimum he already gives, so it would have an impact on me.
I would also miss my kids, but I don't think that's a bad thing, at the moment I have a good balance of kid-free time, but too much would be hard for me, I don't know how once a week is often enough for my ex.
I think it's better for DCs to have somewhere/someone as the main home, with the other parent as an occasional thing. The kids I know who are 50/50 are always a bit unsettled, disorganised and torn between the two homes. My dc know that this is home, dad's is a nice break once a week.