I have friends who do close to 50/50 - their DS spends Tues night with Dad, then Thurs and Fri nights there too, so 4 nights with Mum. He will often spend Sat night with Dad too, especially if a treat / trip is planned - Mum and Dad seem to be able to work it out quite amicably. Although there is a lot of toing and froing, it is a set routine, so everyone knows where the DS will be, including himself. Mum and Dad can spend longer at work when they haven't got DS, and less when he is with them, which wouldn't necessarily work if it was a week in one place, week in another.
The DS (8) is currently quite happy with the arrangement, sees the positives of having two homes and two families.
Personally, the main reason I think it works is that the parents put their son first - it is always about what is best for him, no petty point-scoring, or trying to use him to get at each other.
The suggesation of having stuff at both houses, and limiting what needs to move each time, is a good one. There will always be special things that need to move, but having toothbrush, pyjamas, underwear, some clothes and some toys and books in each place seems sensible.