Here's a past thread on the Panerai metal bracelet:
panerai.watchprosite.com
1. Which is flexible in terms of formal and casual wear?
I consider the metal bracelet more for casual wear. The bracelet is a little too blingy and sporty for format wear IMO, so I'd opt for a brown or black croc strap for formal wear.
2. Which has a better resale value and the market for it?
The Panerai bracelet itself doesn't have good resale value IMO but there is a market for it. If you ever try to sell a panerai bracelet by itself, u'll probably get a lot of low ball bids from people who want a good deal. A cheaper alternative to buying one brand new at full price is to purchase a used one and send it to Panerai to get repolished. When I had my Panerai bracelet repolished, it looked brand new afterwards!
Cheers,
Anthony
As far as flexibility, I would actually prefer the bracelet models when it comes to Panerai Luminor. That's mainly due to the fact that you can always put a leather/alligator strap to any bracelet model but can't quite do the same if the other way around.
I do agree w/ Anthony that for formal occasions, an alligator strap is probably more suitable. However, for casual occations, especially when you engage water sports, then I'd appreciate bracelet as a viable alternative to rubber strap.
There's obviously no denial that from a historical point of view, calf leather strap is the right way to dress up your Panerai but then again, we all need a bit of variety in life don't we?