PacketDesign

Does anyone have operational experience with PacketDesign's Route Explorer or Traffic Explorer products? I'm curious to hear how/if the product helps network monitoring and modeling, particularly an MPLS-VPN service provider network. I'd appreciate hearing about any woes also. We are obtaining some demo units to test drive soon but their products aren't cheap I'd like to hear how they hold up after the test of time and after some user experience.

Thanks,
Mark