Which arm best for SME30-2?

I have tried the Tri-Planar and have the custom machined armboard if you are interested.
All arm are very good and the nice thing about the SME 30 is the ability to change armboard in a few minutes. If money is no object you can have both arms and swap when you want.
The Tri-planar is a very nice arm and did some very good thing while I had it. A trade off compared to the SME V.

I also have the Graham armboard if you are interested. Though I never tried the Graham on the SME it is very nice arm on my TW.

They are all good. It is hard to say which is better in your set up. You have good stuff just depends on what changes you want to make, it is mainly a lateral move if anything.

Paul

If you're going to use only one cartridge, the Koetsu Blue Onyx, ask yourself which arm will match best with that cartridge. If you're going to use multiple cartridges, including perhaps a mono cartridge, the Phantom is unsurpassed which quick easy cartridge swapping (each with its own arm wand). The SME V is a gimbaled arm, the Phantom is a unipivot - each has its own attributes. The SME table and arm have great 'synergy'. A personal preference in the end.
I have both a Phantom and an SME V, each with its own SME made armboard - I use both on my 30/2. As Pcosta stated, switching arm/armboard on the 30/2 is quick, easy, and precise. I like the Universe on the V; other cartridges with their wands on the Phantom.
Don't overlook the Basis Vector 4 arm - it can be ordered with an SME base. A beautiful arm as well.

With the Koetsu is the Phantom a safe way to go.
Or a 9" DaVinci (or when another Armboard is available, the 10" with SME/regular mount ...).

Thomas - I have no experience with the DaVinci arm but use a Koetsu Urusuhi on my Phantom. It works quite well, as most cartridges do with the Phantom.