I'll second what Motnic said. I've had a Nottingham Space Deck with Space Arm and currently own a Space 294. I ran a dual arm setup on the Space Deck using a Micro Seiki MA505 MKIII, and the MA505 was a more dynamic arm. I replaced the Ace Space 294 with a Moerch DP6 keeping the same cartridge (a Karat 17D3). It was a significant upgrade to my ears. Better bass, dynamics, etc.
I will say the Ace Space arms do sound better than the Space arms.
I will say the Ace Space arms do sound better than the Space arms.