Right now, we have just that setup, but every time I've failed over to the new master, we've had to rebuild our spares from scratch and unfortunately this is a multi-hour long process. We can't afford the risk of not having a warm spare for that length of time. We're planning to move entirely to a slony cluster, but I'd like to fail over to a more powerful machine before we begin the slony migration as the current server is already overloaded.
Thanks,
Bryan