Plastic flange vs wax

[mcf57]

About to replace our toilet. I have always used a wax seal. However, I see this fluidmaster 7350 plastic/wax free flange instead. I like the idea of these. Less mess and reusable. They also claim better when plunging.

What are thoughts about these plastic seals. Good, bad?

 

[breplum]

I used to carry one in case there was opportunity to use. Fine if your gaps match.
Not suitable to every installation whereas wax is so routine to use in most any situation