I have both levels in the sense that we converted the diningroom into a playroom which we use first thing in the morning, while I make lunch etc. Often we play in here till babies go down for morning naps and then go down to the basement playroom for the rest of the morning and then back up for lunch.

We eat in the kitchen and use the small bathroom on the main floor too. My diaper change area is main floor too near bathroom although it is quick to grab child's bin and take it to the basement for changes as needed.

Most parents are ok with the basement as they know they are not down there all day. Those that have an issue tend to have lots of issues about a lot of things and too much trouble for me to deal with. I have info in my ads that we have a mainfloor playarea as well as a lower level play area so parents reading that that have issues needn't bother calling and wasting my time.