I was looking at a Magnaflow myself. I've also been scouring the net, tube, etc trying to find vids or audio clips that were half-way decent. There ain't much! There is a decent Flowmaster clip on an Expy that doesn't sound too bad but I've never been a huge Flowmaster fan. When I sold my 90 notch many years ago, it had Dynomax Ultra-Flows on it that just sounded the absolute nutz with hardly any drone inside at all. I've thought about going to one on the Expy but I know the lack of the H-Pipe and true duals will change the personality of that sound quite a bit.

Decisions, decisions, decisions. I may stop by Lou's Custom Exhaust up here in Manchester, NH to see what they have. They're one of the biggest aftermarket exhaust builders around here and come pretty highly recommended so it might be worth a shot to stop by and see what they have to say.

Edit : added vid

YouTube - 2007 Ford Expedition Flowmaster