Jay:
This is interesting. I have exactly the same set-up as you on my
Atlantis & couldn't be happier. The Deores are the plain ones that
Riv had on close-out last year, just plain Deore with no extra letters
or fiddly pads. Before that I had Tektro 720s for a long time (with
the appropriate levers) and they just took too much lever pull. The
Vs work great on long steep downhills and modulate better than the
cantis.
One variable may be cable housing. When I changed the brakes, I
bought some extremely stiff cable housing. Don't recall the brand but
was about 3X as pricey as Shimano standard housing. My cables run
under the bar tape, so plenty of tight bends.
Another variable I haven't personally tested is whether or not letting
the cables "run where they may" would be any different. Even though
the Tektro levers have the same pull as MTB levers, I suspect the
cable routing with the tight bends under the bar tape may create some
additional friction. I have a note to self to see what, if any,
effect freeing up the cables may have but that will have to wait until
the next time the bar tape needs replacing.
Keep us posted on whatever you try. I keep learning new stuff here.
dougP