Arbor vs Narus comparison?

Recently I've been searching for something that is comparable to Arbor to see what else is out there. Someone suggested Narus.

Anyone out there have an opinion regarding the 2 applications and their differences? Or another application that is worth noting?

I am currently using Arbor Peakflow for Netflow analysis against my peering/transit traffic and their Security suite to identify DoS, etc at the edge.

Feel free to contact off-list.

Thanks

As Arbor bought Ellacoya and entered the service control business,
Allot striked back buying Esphion, and it's now called Allot
ServiceProtector. I haven't tested any of those.

Rubens