I actually made my builder MOVE the laundry room to the second floor and paid money for the privelege. Where I live, code requires the washer to be in one of those trays and it has to drain to the outside. Plus the hoses have to be some kind of expensive double insulated hoses just for that reason. In my last house, the 2nd floor laundry had a tile floor with a drain. So if there was a flood it would all drain outside. But I still turn my hoses off when I go on vacation.
Why would you want a laundry NOT on the same floor as your bedrooms? I do up to 4 loads of laundry a day. Who wants to carry all that stuff up and down the stairs? I thought the CW was that the laundry room should be on the same floor as the MBedroom. Of course, I like the closet being in the bathroom too. But I think its weird not to have a door on your bathroom.