Selfdivider,I have heard the Davinci/Dynavector combo to excellent results.It appears to be a superb arm,and has a great reputation.The other two arms also have fine reputations,with the "right" cartridge,but I've not heard them.
From a point of interest standpoint(as it effects sound/music)....I have a dear friend who had a "magnificent" linear arm design,mounted on a high mass table/stand/air suspension....
It allowed for a "stunning",almost unmatched musical presentation,that I and others felt would not be equalled by "any" pivot(regardless of length).
Yet,my friend had owned this linear design for a number of years,and got tired of putting up with the "maintenance" issues,though minor.
So,he switched to a commonly known 12.5 arm,which did not match the air bearing/linear design,in that gorgeous relaxed,colorful presentation the set-up previously had!
Some friends(myself included) were quite dissapointed,because he had something "special" going on in "that" system.......Well-----
My friend must have had something going on,in the intuitive area of what he was looking for....because....
Two skilled,highly experienced and quite gifted fellow hobbyists(Richard Foster,and then Luis Cardona)showed up and "rolled up their sleeves" on my pal's table arm combo....
The results were "astounding"!!!
True high fidelity performance is now being had,from this 12.5 inch arm,and I had always thought it to not approach the performance of the linear design.....I sure was wrong!!
I and many others now feel it "almost" approaches the linear/air bearing" virtues....My pal is now ecstatic,and I must admit to being quite impressed with what a good "long" pivoting arm has to offer....
I can hear "music"!!....Go for it,if it makes you happy!!
Best