The ability of yotta to easily add custom fields without changing any codes has been my favorite part so far! It really helps us keep track our orders & inventory.
I haven't found anything that i dislike yet but it would be nice if they could make some changes like adding an option not only between different colors (e g red) as well just one color - e rg blue etc.. Also when we send emails from internal email addresses sometimes its hard because you'd need special characters which are difficultly added into this product itself(maybe there shouldnt even allow those character at first place). Just do yourself 1 favor by using such great software! We use their services mostly to take care off shipping details/invoicing stuffs instead doing them manually every time.