Hi Lucky2Bhere.
Here's the thing. I called Korg the next day to inquire about it and they told me the M3 is a "scaled-down" version of the OASYS, with the same (or a similar) sound engine.
Technically that's stretching it a bit but I can see why they would say that. Under the hood they look very similar but at the heart they are two completely different engines that sound nothing alike. The OASYS can shape sounds in ways the M3 can't and overall the clarity is far superior due to it's abilities and the fact that it also runs off of uncompressed samples unlike the M3.
The effect engine in the OASYS is also way more advanced and it can run 11 Insert effects at the same time where the M3 can run 5. Also the OASYS has effects the M3 doesn't like the OVerb effect which is just pure silk.
The OASYS also has quite a number of different types of Synth Engines. It can even load Yamaha DX7 SysEX patches straight from the real DX7.
What's your opinion on the two units. I could see me buying an M3 as a supplemental keyboard to an arranger.
You really can't compare them. The OASYS simply does everything better and faster than the M3 in every way imaginable. So if you have the cash and need for an OASYS you can't go wrong there.
If not, then the alternative is pretty great too.
The M3 on it's own is a fantastic product that offers excellent value for money and comes jam packed with well over 600+MB of PCM data. You will have more sounds than you will know what to do with. It's an OASYS wannabe for sure so all in all it's a tidy and excellent product.
Regards
James