I designed this 2-sided duvet with a custom panda graphic (designed by me) for my son who is going away to University in September and I couldn't be more pleased with the final product. Great image quality and colours! Nice feel to the fabric. I haven't tried to insert a duvet into it yet, but I did order a "double" size duvet to fit a twin bed to make sure it was big enough.
Fabric feels really quite nice. It's not cotton, but it has a matte feel with a nice weight. Not like that cheap, thin synthetic feel. Colours are awesome! Just like my original design.
I can't really think of any at the moment.

Vibrant colors! Fits duvet perfectly and even has ties at each corner to keep it secure!
Everything except if you are impatient!
Takes time to receive it