Firstly, the item looks great. Really really good, I love it.
This is not the Gruffalo Shop's fault exactly, but I hate the bottle.
The screw thread for the lid is so long, it takes forever to do up.
When you tip water out, it all sits inside the lid and would tip back on your face once you drank your fresh water if you didn't spot it.
The spout lid is terrible- if you pull it half way, you can only get a dribble of water. If you pull it out fully, the valve allows in an equal amount of air and water which gives a horrible drinking experience (mouth half full of air). There's a noise to go with it.
I considered asking for a refund but as it's personalised I'm not sure I'd get far and anyway, it's the fault of the designers and manufacturers, not this store in particular.