I have both. Haven't used the saffiano yet but have a good feel for it.
Fabric glams are more comfortable to carry and are lighter. Also can get rained on no problem. If you get a light colored one, it can show stains/dirt. There is a cleaner, but it's not perfect depending on what you get on it. Although the glam is relatively worry free, I still don't let my kids get near it when their hands are dirty. And I'm careful where I set it down.
The Saffiano is a little heavier because it's leather, and not quite as comfy because it doesn't squish or slouch. But I wouldn't worry about dirt or spills unlike with my glam because it can be wiped so easily.
I'm not too worried about the bending issue. It wouldn't happen instantaneously. Kids are destructive for sure, but you would catch them doing something to your bag before it could cause any permanent damage with bending/creasing. When I've test packed my bag a few times to carry it around the house there were a few things bending the leather out a bit but it popped back into place no problem. I would be more worried about storing it carefully though. I plan to keep mine stuffed, upright, and slightly separated from my other bags so nothing rests on it for long periods.
The Saffiano looks more sophisticated while the glam is casual only, if that matters to you.
One awesome thing about the glam is the outside pocket, forgot to mention that before.