As a former Spacedeck/Spacearm owner, and current VPI TNT6-HR owner, here's my experience.
I enjoyed the Spacedeck for about 2 years paired w/Shelter 501II cart. After listening to some others' rigs, I felt that I wasn't getting all the music out of my records. On small combo jazz and simpler rock/folk, everything seemed great. Balance is definitely warm, meaning a slight hump in mid bass to low midrange. With full orchestral music, and relatively complex rock recordings(e.g. Yes, old Genesis) my Spacedeck lacked the transparency and clarity to hear all the nuances in the music. It was not easy to follow one instrument in an orchestra unless it was close miked. I knew there was more to hear.
My VPI upgrade was to a more expensive table, and simultaneous with a cartridge upgrade, the ZYX Airy3. However, I did hear my Shelter on a friends' Scoutmaster. The Scoutmaster and TNT6 share a similar sonic signature; better extension at both ends and significantly better resolution. The Scoutmaster might be a bit generous in its bass presentation, with the TNT6 being more neutral. Both tables allow you to mentally lock your attention on any instrument within a large group, and all the images emerge from a blacker background.
Other reasons I recommend VPIs:
- a solid track record of clear and affordable upgrades
- consistently superior customer service(at lease in USA)
- Spacearm's wiring is most fragile you'll encounter
- Easily adjustable/repeatable VTA/SRA on the JMW arms allow you get the most from each record
- The most used tables at every CES, the pros must know something(they aren't free loaners)
Both are nice alternatives. It's a good problem! Cheers,
Spencer