I've probably made remarks here and there about each arm but have not done a formal comparison or review. My Tri-Planar Mk VII has the carbon fiber arm and is the standard length, 10-inches. (iirc) When I ordered it from Tri Mai I asked for copper wiring instead of the standar silver. My 4Point was ordered with silver Kondo wire.
The 4Point design is in part derived from the original Wheaton Tri-Planar; each has a vertical tower for VTA adjustment. Imo the 4Point's VTA adjustment is a bit finer grained. The Tri-Planar has a flat base and does not require a mounting hole. Both support horizontal damping. Both use a v. similar azimuth adjustment mechanism. One thing I really like about the Tri-Planar is once you make an adjustment it does not wander.
With the Monaco I find myself using the 4Point on the Monaco much more frequently. Partly because it has a removable headshell with a v precise fit which makes swapping cartridges pretty easy. Of course the Monaco makes changing tonearms likewise easy. I acquired the 4Point after I upgraded from the Monaco 1.5 to 2.0 based on a recommendation from Roy Gregory, so I haven't used it on other tables. Both arms work very well with the Monaco.
Sound wise - here I'm working from memory - both are very good at extracting detail and both offer very good tonality. The 4Point has slightly better dynamics and offers firmer control in the bass; the Tri-Planar is a wee bit softer, some say it is more romantic. Monaco+4Point yields excellent bass. Each time I have upgraded components I find the Monaco+4Point reveals the combination has not reached a plateau.
At some point, when I can get out from under my current work, I plan to acquire an SME 3012 to try with the Monaco. I already have the arm mount, so if someone else is lookin at that combination or a different SME, Alvin should have the mount.
