The Nania Airway has several issues. One of the biggest being that the crotch strap is very long (and according to Nania/Safety Baby/what ever current name they are using, it has to be this way because it failed crash tests with it shorter) it puts the buckles right into the child's abdomen. There is no way to tell if this would cause serious internal injuries or not since the crash test dummies do not have sensors in that area. But if we follow crash forces we can map out that this may put enough presure into that area and may cause internal injuries to the child. No way to know this foresure without your child being the crash test dummy with "sensors".
Next reason, is because I find it very difficult to install. It has a high belt path and it flat out doesn't fit in many vehicles.
Next reason, it is difficult to adjust the harness and move it from one set of slots to another. If a seat is difficult to use, then parents are likely to not use it correclty putting the child at risk.
There are better options on the market. I much prefer them to the Airway!
Jen E. CPS Tech and mom to 3 in seats!