Good for cold and warmer weather
Both of our 'kittens' love this, although not to share! It can also be a surprise when one is in there and the other one wants it and jumps/sits on the top so it caves in! No harm done.
It was a bit odd that the top isn't rigid, but it pops/pushes back up easily (and we've had it 4+ months now). The benefit now that the weather is warmer is that they can lie on top and use it as an 'open top' bed.
Think we'll buy another one before this winter so they have their own - if that helps!