Even though I've got a sunburst Road Worn Jazz (circa 2008), I really like the Firemist Silver. It's a great color, and it's distinctive. I saw a vintage Firemist Silver P-Bass at a guitar show years ago, and it aged into the most gorgeous silver where a lot of the blue had faded.
But I think that if you're able to go try one in person, do it. You're likely to fall in love with an instrument more based on how it sounds, feels and how well it's set up than any one finish.
And if you're not married to the Road Worn look? I tried the Vintera 60's Jazz bass in the gold finish, and OMG it was a fantastic instrument!
The original Firemist Silver (introduced in '65 and replacing Inca Silver) was, well, silver. There was no blue in it other than the slightest hint - not at all like the current color. Have seen it age in combination with the clear-coat to a light gold or a slight green tint. This current "Firemist Silver" looks much closer to the vintage "Blue Ice Metallic". I would not expect the blue to fade out to silver per se.