I upgraded from an older Spacedeck (with the thinner platter) with Space Arm to a Space 294 and it was a significant improvement. A dealer told me the difference between the Space 294 and the newer thicker platter Spacedecks with Ace Space arm is not as great.
Just recently I replaced the Ace Space 294 arm with a used 12" Moerch DP6. The Moerch arm took the table to a whole new level. The DP6 gives me better bass, improved detail and dynamics. I kept the same Dynavector Karat 17D3 cartridge. I also use a Boston Audio Mat 1 instead of the supplied foam mat.
Just recently I replaced the Ace Space 294 arm with a used 12" Moerch DP6. The Moerch arm took the table to a whole new level. The DP6 gives me better bass, improved detail and dynamics. I kept the same Dynavector Karat 17D3 cartridge. I also use a Boston Audio Mat 1 instead of the supplied foam mat.