I don't have much first hand experience with the A90, but I have been thoroughly enjoying a brand new Ortofon 90th Anniversary SPU mounted on a Thorens TD-124 mkii with an Ortofon RMG 212 tonearm. Coupled with an Audio Research amp/preamp and a pair of vintage Altec Valencia's, if I had a mirror in the living room, I'd see my slow and silly Cheshire Cat-like grin in the evenings as I listen to vinyl. It feels like the SPU is "settling in" as it continues to improve with each session (all in all probably less than 30 hours on it at this point).
Sitting next to the 124 mkii is a recently serviced and setup 124 mki with an SME 3012R arm and a Denon DL-103R cartridge in a Yamamoto HS-1a African ebony headshell going through a Auditorium 23 SUT on into the ARC preamp/amp. Both TT setups sound great and I am still A/B-ing, but at this point, there's a nod to a greater level of detail and soundstage holography to the 90th Anniversary setup.
Due to a clumsy mishap, I recently sent a bent tip DL-103R in a Uwe ebony body to Soundsmith for re-tipping, so hopefully, later this summer or perhaps in the early fall, there will be a fun comparison of the stock v. modded Denon.
Eventually, I hope to migrate one of the cartridge and tonearms onto a grease bearing 301 that needs a good plinth hence my great interest in coming across your post.
