I have the Esoteric P3 and D5 combo and I used to own the X03se. I thought about getting the P5 but decided against it after finding out it uses an inferior transport to what is currently in the P3. It is my opinion that the transport plays a significant role in the sound of a cdp, especially its ability to resolve low levels of detail. I have said this before, to me, low level details is what makes a song sound real and organic. All that being said, to my ears the P3D5 combo is better than my previous X03se. I heard more detail and better separation of the instruments. It should be noted that I decided on the D5 not for financial reasons. I have a digital music server that I wanted to send through the dac. Strangely, the D3 does not upsample. Instead upsampling is done in the P3. The D5 does upsample and has the latest 32bit AKM dac chips. Both of these factors played an important part in my decision making process. And yes, saving some money was nice too.
Without any emprical data, I would guess that the D2 should at least as good as the P3D5 combo I have. But because of the inferior transport, I imagine the D2 should sound better than the P5D5. All that being said, if you do not need digital inputs, I think the sweet spot in the Esoteric cdp lineup is the X03se or X01ltd.