to tell You the truth when it comes to DAC I have no idea which to buy.
If you like more warmth, go with an R2R DAC, or a multibit from Schiit.
If you want a brighter sound to balance out the Atticus, a decernt delta/sigma DAC would be the way to go.
What's your budget for a DAC, and what country do you live in?
In
general terms, a R2R DAC has a warmer, more organic sound, with rounded bass. The goal being to get as close to a vinyl sound as possible.
A delta sigma DAC is typically brighter than a R2R, and can sound more detailed with more incisiveness. When done right, a d/s DAC can sound great, but entry level d/s can add hash and a digital edge and/or glare to the music.
Schiit is a safe option for a DAC because they make some good sounding stuff at a relatively affordable price, at least here in the USA.
Also because they have a huge name recognition within the hobby, so if you for whatever reason don't like the sound of your Schiit DAC, it will be quite easy to sell it.
Schiit does not offer any true R2R DACs, rather they go about it in a different manner and refer to it as "multibit."
I have two entry level Schiit DACs, a Magni and a Magni multibit. To my ears, the multibit is superior to the non- multibit version.
Chord makes some good sounding stuff, as does Audio GD. Other DACs that are good come from Denafrips, Holo Audio, and Lampizat0r, but much of those DACs I mentioned are expensive.
Until you figure out if you prefer the sound of a R2R DAC or D/S DAC with the rest of your gear, I'd recommend a Schiit or an Audio GD DAC, not stupid expensive. Once you know what sound you're after you can move up the line and get a better DAC.