I've not timed it but it's definitely a lot slower than it was in Tiger. The funny thing is I've noticed that when I restart or load Windows then go back to Leopard it doesn't take no where near as long to load.
Your boot time is pretty good. I don't think you can realistically expect anything faster than that. Since most people don't boot often anyways, a 30-40 second wait really isn't a big deal.