BLUF - wished I did this sooner - almost the perfect design for my use, fixed all my PC sound issues, adds convenience and features, top notch sound, build quality stellar. Used with Fidelio L2 and X2.
*edit* - tried the Fulla 2 with my work laptop, A/B vs onboard sound...it was an instantaneous OMG!...huge improvement noticed. I almost couldn't bring myself to bring it back home. Added a bit of detail below...but onboard was the muted woolly equivalent of a nasty cold vs Fulla 2 being at my peak.
Random ramblings/impressions:
After much debate I pulled the trigger. My Fulla 2 arrived a couple days ago. First addressing the typical "issues" Build quality superb, no marks, knob is a centered as I can see even "looking for an issue" nothing. No scratchy, nothing. USB ports are tight, but better tight than loose. With low impedance and high level input, you can tell slight channel imbalance at the very bottom. Absolutely not an issue for me as it is well below listening level and can be adjusted with a minor drop in input (aka lower windows a bit).
Other thoughts - I had been using my friend Magni and loved the volume knob...Fulla 2 blows it away due to size, feels smoother and more precise. Overall design and features practically "custom made" for my needs. Lets me have one digital connection in from PC, always on volume knob for the headphones and a fixed out put to the speakers (self amped). Easy to swtich if kids in / gaming with them or wife wants to control...no fuss. Half the size of the Magni - but denser, very solid.
Sound, the clicks/pops from the onboard are gone, nice clean noise floor. Sounds quite a bit better than the onboard (realtek ALC892) whether direct or through Magni amp. Better than the Earforce ESS to Magni. Overall tonality sounds like the Magni 1 and from what I remember my friends Schitt stack 2.
I do have a LG V10 which has ESS Sabre 9018C2M digital to analog converter chip inside, as well as an ESS 9602C headphone amplifier to allow quick A/B (toggle enabled). The V10 is a heck of a solid setup for portable use and moderate impedance...so how does it compare? Well they sound different, regardless of volume. I guess I was really thinking the sound would be tonally about the same and the differences would be on higher volume / bass control / minor special clarity, etc.
The Fulla 2 sounds larger / bigger soundstage by a bit, most notably it also resolves more detail...I hear little mixing errors, fine detail and the like. The extra power is also immediately evident when I start driving mid to higher volumes with heavier bass content. The V10 sounds a bit smoother with rough content...can't decide why, the Fulla 2 could be just resolving more, perhaps is tuned a bit brighter, perhaps is a byproduct of very low output impedance with lowish headphone impedance. In my experience, higher output impedance in low impedance drivers tilts sound with a fuller sound / more bassy...but it is looser / muddier.
On the L2 the bottom line is the fulla 2 is better all around no caveat. On the X2 the Fulla 2 is better on any technical description I could give...but when dealing with brighter / poor recordings, the fulla 2 with the X2's upper end light grain can be a bit less pleasing to me than the slight muting/veil the V10 puts on.
*Edit* added A/B results for work laptop, driving Fidelio L1s. I did some A/B against the work laptop on board. The improvement was almost absurd. Onboard sounds thick and woolly in comparison, lacking all detail, specially collapsed. If your onboard sound implementation is anything at all of this quality you will be absolutely floored by the Fulla 2./end edit.
So I said almost "custom made" for me? Well - my perfect world recommendations for Fulla 3: slightly looser USB openings, cut the aluminum to allow a bit more space on the rear ports...not an issue for me, but limits to smaller connectors, add a rear line-in...we've run out of room but an optical in with 192 support. Maybes: switch with dim LED (I'll take Fulla 2 set up over the Magni bright LED). All the things I listed outside minor aluminum chassis tweaks would cause cost increase or removal of a port I like more....
Recommended? Heck ya. Unless you have hard to drive cans, I would probably skip the Magni / Modi and go up a level. Once my friend gets his HD6XX in, we'll try an A/B with a Magni/Modi 2 stack, adding in some other cans like some modded Hifiman HE-400 and a few others. I have some IEMs (Shure E4s, RHA 750), Grado SR80 if anyone wants impressions with those.