Actually, my Topping DX7 Pro has been pretty solid for me too for somewhat of a budget AIO DAC/Amp, not bad to get started, I think. Honestly, as I listen to my Empys more and more, when I think about eventually about upgrading DAC/Amp, I'm honestly lost on how to move forward at this time, at least partially because the different pads provided leave me completely spoilt for choice, and there's really two potentially diverging paths based purely on what pads you want to primarily use, in my view. It is really like having two different headphones.
With my library and chain, at least, I increasingly find myself drawn to the Alcantara pads. They're just very even handed and versatile, and since the Empys/my brain have burned in, they sound both more natural and also resolving in general. At first, to my ears, the Alcantara pads simply sounded dull and cold. But now, they just sound effortless, airy, the soundstage is larger, separation is better, details are easier to pick out. The Alcantaras are the intellectual choice, in my view.
In simple terms, I find that if the recording is not the best, the Alcantara pads are going to be more forgiving. Conversely, if the music is really busy and has some pace (from Dizzy Gillespie to Ride the Lightning era Metallica), the Alcantaras are going to provide a better, more cohesive presentation. On my chain, in some scenarios, the leather pads may struggle to keep up. Using High Gain on the DX7 pro, I also find that the bass gets boomy and harder to control with the leather pads. That may possibly be fixed by better amplification, but perhaps not.
The leather pads- how to describe it? Vivid. Perhaps like romantic fine dining, just a few morsels at a time to be polite to your date (and in acknowledgement of the size of the eventual bill)? But if the food and company are so perfect, who wants to be polite?

So the volume goes up, and it can all become fatiguing, at least for me. Some self control is in order for longer listening sessions. However, they definitely have a place. I have stated before and will repeat again, female vocals are unbelievable to me with the leather pads. Every time I hear Tori Amos, Siouxsie Sioux, Billie Holiday, etc, with the Alcantaras, I know, deep in my heart, the leather pads just have to take their rightful place on the Empyreans. Literally hair-raising.
I was more or less set on saving up for a Qutest/GSX-Mini or TT2 and then eventual M Scaler and just eschewing more intermediate upgrades along the way, but it seems to me that a fair number of people have tried and bailed on the Chord products with their Empyreans. The Burson products seem to be very well regarded around here, and would definitely save me some money. What about the Benchmark HPA4, as I do like the AIO concept given my limited desk space? At any rate, I'm up to about page 550 on this thread, and have been taking notes, thanks to all who have contributed!