Please delete, question answered thanks
Hi @Sorena_,
Both Helix Classic and Eupho Classic are older than the newer Helix Syn and Eupho Syn models.
Both Helix Classic and Eupho Classic have a direct feel on the prostate where both Helix Syn and Eupho Syn have a more subtle feel.
I have all four models in my Aneros toolbox. I started my Aneros journey with Helix Syn in early June 2012. Helix Syn is recommended for absolute beginners in anal play of which I was one. So Helix Syn was a great introduction for me in my Aneros journey. Five months later I switched over to Helix Classic which has a more aggressive feel. Helix Classic is a favorite model of mine.
Also I use either Eupho Classic or Eupho Syn in all my sessions. The Eupho has flexibility and it "dances" upon the prostate. I use Eupho as a session opener.
Hope all this helps!