Can't say how much of an upgrade the Graham would be over your Space arm but I would lean towards the tonearm first. I own the ADS and it is a god send so this really is a hard decision.
Tax return burning a hole in my pocket
Ok, I have never won an award for being fiscally responsible. And, I really like listening to vinyl. And I have about 1500 lps, and about another 300 very nice used ones that need cleaning that I don't seem to catch up on. I have a highly modified Nottingham spacedeck, one off bearing, heavy kit, wave mechanic, custom SRA base. Nottingham Ace Space arm and Benz Micro Gullwing SLR cart. Now, help me spend my money, Audio Desk Systeme ultrasonic cleaner or new Graham Phantom tonearm. Can't afford both. Thanks for your input. ( phono amp is Herron VTSP-2 ).