Better than coolie style metal bottles, as they're difficult to clean, and you don't know where you stand.
The colours are fantastic. Just like the pictures.
The mechanism feels solid, and it shouldn't open in a bag.
2 carry handles - 1 solid plastic (tucks away neatly) and one lanyard.
2 holes, 1 for air so you can swig to your heart's content.
Motivational messages aren't cheesy, and they cover both major measurement units, as well as morning and evening timings.
Included brush, is.... Brushy!
No plasticky taste/smell.
Wide brim, which means fizzy drinks don't overflow when pouring, and cleaning is easier.
Good draw on the nipple bit. Just wide enough to glug if you're parched.
The initial image makes it look like you're buying 2. Took me a while to figure it out. (At which point I bought 2)
The brush isn't quite as wide as the bottle, which means a little extra work.
It would have been cool if they'd provided a rubber 'nipple' for people who like that kind of thing.
Better than metal ones.
Cooler colours than I've seen elsewhere.
Well provisioned for travel
I'm a happy bunny.