I installed Alfresco for the first time today.
I'm running it inside a VMWare Ubuntu Server setup and did notice that it takes a while to get the first page up and running - approximately 3 minutes.
However when I first installed it I noticed that it took considerably longer than that. Not an hour, but about 10-15 minutes. The big problem turned out to be that I didn't allocate enough RAM to the virtual machine and it was spending a lot of time swapping. That might be a good place to start.