I can not think of any cons to buying this product with exception to the cap, I often pour too much syrup out of the bottle and closing it can be a little bit of a hassle when the syrup collects at the edges of the cap, but this can easily be prevented I just tend to be on the clumsy side at times. (amazon.com)
Some parents have complained about the extra piece, the vent, and how it is a little bit of a hassle to clean. (babygearspecialist.com)
Firstly, because it comes with the integrated wheels, it is slightly heavier and bulkier than the car seat we are used to — this isn't a massive issue, but as the baby grows and gets bigger, that bit of extra weight and bulk of the seat can make putting it in and out of the car a little bit of a hassle. (thedadventurer.com)