Good questions. I originally used them for two setups. That’s no longer the case, but I’m keeping both “just in case” I want to put together a second rig again. I could definitely be happy with either the 1541 or the ADI-2 DAC. I actually tried to find a convenient software PEQ to use with the 1541, but found nothing I like (closest thing I found was using Apple’s AU plugin with Audirvana, but I’m really looking for a lightweight system-wide solution). I’d say that the decision should be based on how much your system benefits from EQ, since that’s the ADI-2’s killer feature. For, say, the Andromeda or the PMx2, there isn’t much equalization needed. For the HD800 or the PM3, it’s a game changer. For the HD600, it’s a bit of a wash. For speakers, I think it benefits most systems by helping fit room acoustics. As for the Gungnir Multibit, it doesn’t sound different enough to me from the 1541 to justify keeping. Yes, I tested volume-matched, with a switcher, and for both short and long sessions. They didn’t sound identical (and I have stronger evidence than “I said so”), but the differences washed out in seconds as my brain adapted. I’m also probably the only person who cares about this, but I found the Gungnir Multibit’s (and Yggdrasil’s) relay click unbelievably obnoxious. It goes off all the time when the USB input has no lock (i.e., connected to a sleeping laptop), and it’s plenty loud enough to echo through a quiet house at night. And since you’re not “supposed” to turn off multibit DACs, I’d have to remember to change inputs all the time, which annoyed me. That, coupled with the 1541’s vastly better feature set, made it a no-brainer to sell the Gungnir Multibit.