We did test it, and there's good light and vision from the inside. Which is why I do bring the scarf to cover it up. Cairo definitely sees outside - he 100% responds to stimulus (he will even panic if he can't see us), though he acts as though the Birdie GoGo is his magical protector cage against the world (he'll practice vocab and start chattering away inside).
I'm very happy with it, especially for the price. It works for our lifestyle - lightweight, easy to maneuver, etc. I live in a hot and humid country, so this is perfect for us. We don't need all the ++ of the Pak-o-Bird, but if you do need all the extra features then you'd have to carry a separate bag - like I said, we carry essentially a baby bag for Cairo with everything from wipes to toys, chop to spray bottle, so we're quite happy with it.
The only foreseeable complaint is that because it's mostly mesh, it can sag at the food bowl points if your bird continually steps on the food bowl (but I tackle this by constantly switching which side it's on).