Pretty much all of the time I have seen a hard L or similar on the panel if there is one. If not it would be on the door. Either way there is always a seal unless you want the water to splash out. So I would tend to believe that "Well, if he maybe measured correctly would we need that?", yes it in needed. And perhaps research should be done before making such a broad statement about him measuring incorrectly.

We have a fremeless shower door, and it has clear gaskets. It was laser measured, and fits perfectly, but without a gasket, water would be all over the floor outside the door. It's necessary, in my opinion, and I don't even notice it. It's easy to peel off, however, so take yours off, and see if you can live with the leakage.....

Also depends where the shower head is aimed but the company I work for and all the local companies i know of use them. The largest shower door hardware supplier in the country sells them by the truckload as well as every door supplier I know of.

Thank you for telling me like it is! I read about the "measurement" thing on another page. Obviously what we see in the magazines is not what we really need on our doors at home.

Take it off and see what happens. If there is not water outside, leave it out.