I really love the collapsible design of this product. I just received it yesterday for my 40lb English Springer Spaniel (ESS) and I'm debating whether to keep it. I truly can't imagine a dog bigger than 30lbs fitting in this. My ESS will be fine for short periods but very tight on him. He doesn't seem to like it because of the smallness and not being able to sit-up in it, properly. I'm going to see if he changes his ways a bit more. I actually wish they had an extra-large. Nice, quick design though. If he starts liking it, I will keep it, as I only use it sparingly with him. 

Pros: Nice design, quick delivery. 
Cons: Much smaller than anticipated, would not recommend for a dog larger than 40lbs if you want it to sit up.