If you listen to mainly 50's and 60's music, the spu will be hard to beat. It's forward midrange presence just makes magical music. It can be a bit to much in modern recordings and music.
The a90 is the better cartridge for all types of music.
IMO, I would buy the a90 and down the line a classic E spu. That is the spu that really gives you spu magic.
Turntables: Pioneer Exclusive P3 & P10, TW Acustik AC-3 / Graham Phantom, Linn LP12/ Naim ARO Phono: Pass XP-25, TW Acustik Cartridges: Lyra ATLAS, Dynavector XV-1s, SPU Royal & Classic E, Ortofon A90, Linn Troika, Technics EPC100Cmk4, ESC Denon 103r, Denon DL-S1, Audio Technica AT25. EQ: DEQX HDP-4 preamp: cj GAT, Pass XP-20 amps: D'Agostino Momentum Stereo, cj prem8a - teflon caps, speaker: Wilson Maxx 3