We have a bunk bed with dd (6) at the top and ds (4) down the bottom. My god the linen change is a pita but dd now makes the bed herself. It never looks immaculate though.
We're considering the 'Captain Jack' from Super Amart as we don't have an Ikea here. We looked at the cj in person today and it's much lower than the bunk we have atm. The mattress is low to the floor with slats but I'm willing to air it out every now and then because the current bunk takes over their whole bedroom.