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.
             -paul-