You'll get a lot of differing opinions here, but in the end it depends on what you want to hear (and where and when you want to hear it).
I've got an AeroTurbine and LOVE the way it sounds outside the VX pretty much throughout the RPM range. But I'll admit I'm not too thrilled with the droning INSIDE the cabin at around 2200-2500 RPM. It's kinda boomy and I'm investigating dampening options.
Gussie2000, on the other hand, has twin dynomax super turbos and they sound damn near stock on startup and idle and "normal" driving - but get on it a little bit and they growl like mad.
If I had it to do over again - which I may if I can't sort out this droning - then I'd seriously consider those.
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