Gotta say...very, very happy with my Flowmaster Off-Road Extreme. I've had it for a couple of years now. Deep growly sound, not raspy.
There are two video (with audio!) clips in my member gallery, comparing the stock exhaust sound with the Flowmaster sound. If I were more of a genius, I probably could have figured out how to link those clips to this post. (Can anyone help me with that?)
As a bonus, the muffler is a cool-looking black diamond-plate steel. Coupled with a carbon-fiber (or fibre, if you're in the UK) exhaust tip from eBay, I now have a color-coordinated Ebony VX. I ever roll it and get stuck belly-up, I'll look AWESOME.
OEM roof rack, Thule Xpedition 696 rack, Rancho RS9000 shocks, OME 913 coil springs, 3" lift, American Racing Teflon Chambers wheels, Yokohama Geolandar HT/S G051 tires (275/70/16), Energy Suspension greaseable bushings, steel-braided Kevlar-reinforced brake lines, WeatherTech wind deflectors, Malibu 18w driving lights, Plasma SuperWhite 100w headlights, NGK Iridium plugs, K&N drop-in air filter, Optima Red Top, Psychos2 rear-door subwoofer enclosure w/CDT Audio 10" sub, Blaupunkt subwoofer amp, iPod Video 80GB, Kenwood KVT-617 DVD head unit w/7" motorized touch-screen, Kenwood GPS HD navigation module, Kenwood iPod adapter, Kenwood back-up camera, Sirius radio, Flowmaster Extreme Off-Road muffler (black diamond-plate steel) w/ carbon fiber tip, Ford Taurus OEM cup-holder/coin tray (single-DIN/lower bay), personalized license plate "ORBITAL", 3M window tint, debadged, removed rear seat, custom 'radiation symbol' side magnetic signs, VX Concepts front skid plate