AdrianLI wouldn’t say Magni is heresy, though the older models I heard were more of a side-grade than a noticeable upgrade. I doubt the Magni 3 would sound muuuuch better, however the input layout, ergonomics, and aluminum style might be nice.
I’d get a Magni before an O2, but if I already had an O2 I would wait for a more significant upgrade. If you want one for the nightstand and one for the office, get one of each!
AdrianLIn my opinion not really an upgrade unless you need more power for some reason. Sound becomes audibly transparent in the realm these amps operate in. The vast majority of DAC's will be the weak point - not the amp. And with that said, hearing differences in DAC's is also like impossible. All good designs.