I feel like a ton of people on here have this bed, and I know its a great option for a kids bed when its just a regular daybed. I'm wondering though if its comfortable when you pull it out to be a king? Did you buy the mattresses from IKEA or something different to make it more comfortable when its a king? Also does it seem sturdy enough weight-limit wise?

This would be for guests but they are in their 60's. They usually stay 3-4 nights at a time. Trying to decide between the Hemnes and just a regular daybed with pop up trundle.