It's a bit dangerous to use any technique without testing it thoroughly, almost as bad as using a screwdriver for everything.
CARD works great with IOS if you follow one tiny rule. Make the layout narrower than what FileMaker suggests. For instance, I find 280 works far better than 320 for the iPhone due to problems with scroll bars. You can use any width but I prefer my layouts to now sroll to the right...
CARD has noticeable problems with Windows 10 and I assume the same happens with Macs.
The problem for me is that CARD works in relation to the window it is called from, which is how it is described and that window can be moved before the card window is opened. This means that if I move a window to the lower right before clicking on the button, the card window may be truncated and cannot be adjusted. Moving the window to the left means that the close button may be hidden and the user suddenly confronted with a modal dialog they do not know how to close.
Yes, the frozen window dialog can be closed using Command+W and the window dragged into a better location, but your user isn't going to be happy.
Using a Modal Dialog solves the problem in Windows 10 and probably Macs.
The dialog is nicely centered on my screen (with a few script techniques) no matter where the original window is.
DIALOG overcomes these problems and I can open a modal dialog (the same thing) and center it on my screen exactly where I want with none of these problems...except I have to think and add about 6 script steps for variables, etc. Of course I learned these techniques 20 years ago using 4D...