Yes, I've compared. I owned the Dulcets for about 14 months before trading up to Veenas. I loved the Dulcets. I also like the Totem sound, and own an old pair of Sttafs that I still enjoy in a second system.
I had Totem Model 1 Sigs in for a direct comparison, alternating between Naim Nait 5x and Naim Cd5x, and Arcam CD 23. I liked the Model 1s very much; they have a very pleasing musical sound. However, the Dulcets, in my room, in my system, outperformed them in most hi-fi elements you care to name. Certainly the Dulcets had superior soundstaging and imaging, more potent bass, though nicely controlled. Hi frequency detail and mid range richness, voices, were closer, but I felt the Dulcets had the edge there too.
However, the Totems still held up better all around than that analysis might suggest; still very nice musicality. I think my electronics may have been a better fit for the Dulcets, and might have been a bit current shy for the Totems. I haven't heard your Plinius personally, but have been told by knowledgable sources that it is a particularly good match with Totem.
I'd love to hear about your experience with Plinius and either or both of these speakers, if you should get the chance. Then again, I would have expected the Hawks to be pretty fine with that amp; I'm not sure just how much improvement you can expect, unless you are set on a standmounter.