Did own the Triplanar VII U2 for quite a while and made a lot of comparisons with it, mainly against Graham Phantom first generation (which was replaced later until Supreme) with various cartridges.
The Triplanar was ok in the time when Graham 2.0 was the current one, but every comparison against Graham Phantom was disappointing for me. The Triplanar is grossly overrated, in no area, with no cartridge it was able to stand against Phantom Arm. That one is faster, shows much more detail in every frequency area and it works also with a lot of carts at superior level. The Triplanar looks solid, but it isn't, the energy transfer is mediocre. It is ok with cartridges which do not reflect any or few energy back into the Arm or are low in weight (Zyx is a good match for example). Koetsu, Lyra and others which need a Arm with good energy transfer, solid bearing to shine on their best, work much better with Phantom. Made these comparisons on same Turntable, same electronics and correct installation. The Kuzma 4P is also a loser compared to Phantom Arm, slow, it simply does not have the headroom and subtle details and so on other Arms can deliver, also a comparison on same turntable with identical electronics was done for that. But there will be other opinions who will write something different ...
The Triplanar was ok in the time when Graham 2.0 was the current one, but every comparison against Graham Phantom was disappointing for me. The Triplanar is grossly overrated, in no area, with no cartridge it was able to stand against Phantom Arm. That one is faster, shows much more detail in every frequency area and it works also with a lot of carts at superior level. The Triplanar looks solid, but it isn't, the energy transfer is mediocre. It is ok with cartridges which do not reflect any or few energy back into the Arm or are low in weight (Zyx is a good match for example). Koetsu, Lyra and others which need a Arm with good energy transfer, solid bearing to shine on their best, work much better with Phantom. Made these comparisons on same Turntable, same electronics and correct installation. The Kuzma 4P is also a loser compared to Phantom Arm, slow, it simply does not have the headroom and subtle details and so on other Arms can deliver, also a comparison on same turntable with identical electronics was done for that. But there will be other opinions who will write something different ...