The order of preference depends on a few factors, one of which is the speed at which the peer is able to upload.
With our tracker, another HUGE factor is having your port forwarding setup. On most traditional internet connections, your modem will either be attached to a router or have a router built into it. This takes all of the IP addresses of the computers on your home network and masquerades them to a single IP address that their connection will use for the internet. The problem comes in whereas your router needs to know what port you are using for your torrent client, as well as the IP address of your computer on the home network in order to forward the connections to your torrent program properly. If you do not do this, with our tracker, it will become extremely difficult, but not impossible to get upload traffic, as this will bounce you to a very low node priority if it is not configured correctly.
I just thought I'd point that out. In my case, my network is a little more complex and advanced beyond the need for port forwarding (at least for my server and my laptop), because both of them are on their own dedicated IP address as far as the internet is concerned, but this is not the case with most users.

