Honestly the I4's are the lightest, comfiest goggle system I have ever worn. They cut tight into the jaw line whilst leaving a good space between the mask and your mouth for great ventilation and communication. All of Nexus were so happy when we got ours before Paris as the field of vision is notably better than anything else out there. They won’t be for everyone due to the size; they were designed as an athletic Pro goggle. Hence the reason DYE will continue the I3 Pro, so we will have 2 top of the range goggles to hopefully cater to everyone’s needs.
Hope that helps to explain them further. Keep an eye out over the next week or so as I'm sure a small initial batch will be arriving soon.