This is the mic I've been using for a few years. I haven't noticed it being so strident on the highs, but I'm a baritone, so maybe that's the difference.
I've always felt this mic sounds like all the good things from a SM58 and none of the bad things. I've compared the two side by side and thought the 58 had slightly more low end, but that the low end of the D5 was, while as warm, was a lot more articulate. The mids are similar and there are a considerable amount more highs on the D5. When I eq it on my PA, I usually cut the high mids about 2 dbs, keep the highs pretty flat in most rooms, low mids to taste as per room differences and boost the bass about 3 to 5 dbs depending on the room.
That seems to be a very accurate representation of my voice. I haven't noticed much more sibilance or plosives on this mic compared to the others I've used (which admittedly, hasn't been a whole lot, mostly 58s, beta 58s, a couple Audixes, and a Senheiser).
I tend to sing fairly close to the grill, not quite "eating" it though, so I usually don't have problems with volume drop offs, although, I do pull back a ways when I play the harmonica so that it's not too loud.
All in all, it's my favorite live vocal mic I've used.
I found this demo on Youtube to be a fairly accurate presentation of it vs a SM58.
http://www.youtube.com/watch?v=r2-KKoAtP9Y
Compared to the Audix mics I've used (I haven't compared side by side, so this might not be accurate) I've found the D5 has a less strident high end, with less plosives, and an overall warmer, rounder sound.