Sorry it’s taken so long to respond.
I have direct experience w/ the Vega G2.1 - I own it. So, take my experience with a grain of salt as we all tend to promote what we purchased as justification. Please note, I had previously auditioned the Lumin U1 - not the T3 with the DAC. I auditioned the Lumin streamer when I was considering upgrading from my Aurender N100H. I ended up buying the Auralic Aries G2 streamer which was a nice upgrade over the Aurender and was better (to my ears) than the Lumin.
That said, the real value (and danger) of Auralic is going to their ecosystem.
When used together over lighting link (their proprietary operating system) (Vega/DAC and Aries/Streamer), they share resources and it’s clear that 1+1 >2. And while using Lighting DS - their music library management system, the Vega as a DAC receiving a stream from the Aries sounds much better than using Roon over the same system.
Used together (i have the Vega G2.1, Aries G2 and Sirius processor) connected this way and it has equalled or eclipsed the performance of all competitors up to about $40k. Of course, I have a lot in my front end with these three boxes, so it should be at least pretty good. But, I’m willing to go upstream from there, and the only thing I’ve heard to date that might be better is the Ideon Absolute and Epsilon. I’ve auditioned DCS and the new Linn reference. They were good. But not better. I’ve also spent a fair amount of effort optimizing the signal to the Aries and that has paid dividends.
The Vega G2.1 DAC/ streamer/preamp is competitive as a standalone unit at its nearly $8k price point. I’ve compared it directly to other DACs in that price range and I’m comfortable with its relative performance. I haven’t heard the T3 so I can’t say which I believe to be better.
I will also note that the Vega has an analogue volume control which is nice. I don’t use it personally as I have an integrated amp, but I tried it and it works well - and is better than a digital volume control.
Lumin is a fine company. I’m sure you’ll do well either way you go. Hopefully you can audition both as that would be the best way to know how it would work in your system/room.
Best,