yea- im not to big on the raspy tone of X pipes either, but in all my experience of my own car, and my friends cars, SLP and Magnapacks sound good while being revved at IDLE with an H- but when you drive it, they are IMO nasty.
Good friend of mine had Magnapacks with an H- i dont like magnapacks as is, but with the H, it didnt sound bad but just not up to its potential. It sounded good while being revved at idle but when he drove it just didnt sound like it was all that. He put an X on it, and even though i dont like the way magnapacks sound- i had to hand it to him, it sounded pretty decent.
try and find sound clips with cars moving and stuff on youtube. pay attention to how it sounds when the gears are changed and throttle is applied at load.
To my knowledge, Magnapacks aren't chambered, and the general rule of thumb i've been taught is: Chambered mufflers like Flows and MAC get H pipes and the Magnapack and SLP types get X.