I've had the A1 and now have the X1, but haven't heard the T2.
Nevertheless, I would choose the T2. The A1 is a nice enough sounding unit but the Wolfson DAC chip it uses is quite dated and to me does not sound as good as the current series of ESS chips. For example, I think the Mytek Brooklyn Plus (which I also own) is preferable to the Lumin A1.
But I would expect the Lumin T2 with the current ESS dac chip to be closer to the X1 in sound quality and to surpass the older A1.
Nevertheless, I would choose the T2. The A1 is a nice enough sounding unit but the Wolfson DAC chip it uses is quite dated and to me does not sound as good as the current series of ESS chips. For example, I think the Mytek Brooklyn Plus (which I also own) is preferable to the Lumin A1.
But I would expect the Lumin T2 with the current ESS dac chip to be closer to the X1 in sound quality and to surpass the older A1.