I'd prefer the "old" model with USB connection because it doesn't give much up in terms of usability but has a considerable upside for security. With Bluetooth all that's needed is a firmware exploit (which is a realistic assumption, we've been there) and an attacker only has to be within range of a few meters. He wont be able to steal the private keys but he'll be able to completely empty any wallets.

Note: the following paragraph might not be true anymore, see below comments.

Keep in mind: all the bluetooth, screen and button IO goes through an unsecure processor which then asks the secure chip to sign something. So exploiting the unsecure part pretty much defeats the whole thing.