V1, I've had it like 5 years. D 3020 is a USB DAC too. Seems the 3045 is also a headphone amp, 3020 has 3.5mm out and its garbage. With UE TripleFi 10's it sounds significantly worse than my phone.V2 or the original? And sub volume I don't think really exists, usually you adjust on the sub itself? Or do you mean there's no crossover settings?
The NAD 3045 seems a little more interesting (though double the price) since it's a USB DAC as well.
On every AVR I've had I think I've always had the option to adjust LFE gain. No Crossover either.