This is awfully subjective. But the post above is exactly why I didn't want to get any axle backs whatsoever. No offense to you. But coming from previous V8 mustangs before, I know that sound is just part of the equation. My '94 chopped like it was going to stall any second half the time. But I couldn't hold a candle to a stock coyote.
That being said, with respect to the 3.7 in particular, it has a unique, almost exotic sound to it. It's almost counterintuitive to what most people would expect to hear out of a mustang but, it sounds good nonetheless. Now, if only there were a way to eliminate that god awful popping on deceleration, I'd really enjoy opening this exhaust up - just a tad. I can't say I'd fathom that spending $600+ on average for an axle back is tantamount to gaining any respectable difference in horsepower over stock but, if I happen to come across something that retained the nature of the stock system but simply increased the volume a tad (Corsa, perhaps), I just might take the dive.