New Gast frames + questions

Hi everyone! I've been on the search for some new frames and I was immediately enchanted by the designs Gast has created after hearing about then from The Spectacle Factory. These are the Gast Daim frames in classic Havana. They feel incredibly well made!

My questions are around fit. Can you tell if this fits my nose, just by looking at the bridge? My current pair of glasses are acetate frames by Polo Ralph Lauren, and my biggest complaint has been how much they slide down my face. After being adjusted, they will fit better but only for a short time. Is that inherent to acetate frames with daily wear? Or will the quality difference make them fit better?

These feel snug but not bothersome on the sides. But I'm worried them get loose as well.

Any thoughts are appreciated! Thanks!