I would say PBR is the best solution if you want to achieve a strict traffic separation (www on one link, and the rest of the traffic on the other link). However, it is neither an elegant nor scalable solution, and can lead for instance to the effect that one link is empty while the other is overutilized.
You also have to find a solution for making sure the inbound traffic (back to your client hosts) is also respecting this traffic separation. One way of doing this would need PBR together with NAT where all www traffic would be policy-routed out one link, and NAT-ed on the router. The outside address of the NAT translation could be advertized as a host address and www traffic from this address would also return via this link due to the more specific advertizement. Another option is using a proxy server.
Bottom-line: PBR gets quickly complex, and you may want to consider using a Quality of Service (QoS) configuration where you give higher priority to non-www traffic, and load-balance across both links. This is a more scalable and elegant solution, and would achieve the same goal. Using QoS you can guaruantee bandwidth for non-www applications, or even give them strict priority. This is also more useful in the event of a failure of the T1 or fiber link where PBR has no way of protecting the non-www traffic, while QoS would protect it also.
BTW: I like you provider selection policy ;-)
HTH, Thomas
