I've got both available to me, and prices for a used Oasys are actually a bit higher than prices for a Kronos here in Los Angeles. If money is pretty much a wash between them, should I be looking at the newer Kronos (shiny!) or the Oasys (old and cool)? And why? Projected use will be recording and some gigging. I don't need to have piano-weighted keys, by the way. I started on a piano but transitioned to a B3 and a Fender Rhodes 88 early on.
I would say the Kronos would give you a more up to date sound and experience, thats not to say the Oasys is out of date (far from it). It's still an incredible sounding machine. The Kronos with 9 sound engines offers an incredible playing experience and every aspect of the sound is editable. If you don't require weighted keys you can get the 61 note version or the 73/88 which are weighted. I've played one and the Rhodes sound is incredible and the B3 sound is great also. Good luck with your decision.