Dear Songofthesea,
No problem with your indecisiveness. I suffer from that too. Of course we all want to get what we pay for right?
If you love the pashmy nylon then go for it. Don't keep worrying that you'll get something better just because it's "just" nylon.
If you love the bag then keep it. Lately nylon bags, especially designer ones are also keeping up in terms of durability and beauty. I've heard
prada bags still look new after 5 years of use.
I also read that the tod's nylon is now waterproofed so that means a great bag rain or shine! Although some leather bags hold up in the rain, would you use your leather bag even in a slight drizzle?
If I were you I'd keep it. My next purchase will be a Tod's Pashmy Nylon (i have a pashmy leather and I don't think I'll use it in the rain). Plus we don't have a Tod's store where I live so I'll have to wait til my next trip to anywhere where there's a Tod's store.
Personally I've been wanting Prada Nylon for so long because I've read it's value for money. What prevented me from buying one is the lack of feminine and useful designs (ie outside pockets etc). They look so unisex.
Good thing tod's nylons are really made for fashionistas like us. And even if it's nylon, all the zippers and the handle drop makes me really happy - the perfect travel bag! Plus it's so lightweight!
Good luck!