I think you could solve this using SPDY, which lets to send an expected follow-on request in the same stream of bytes before it has been requested - originally designed for things like CSS but it should apply equally well here (especially given the UUID URL caching semantics)
Whether or not that's more efficient boils down to how much the server can predict the client's behavior though, right?
I'm just thinking that if the server was configured to respond with the /value/ reference and then immediately follow that up with the resource, your client doesn't really have much say in how noisy the conversation is over the wire.
