This is a magnificent keyboard. I bought one independently. For a Mac user there is one problem which is that if you wake a connected Mac with it the keyboard then goes dead until it is unplugged and plugged. If you wake it with a mouse the keyboard is fine.
Moving from a mechanical there really isn't a comparison. It's a very different experience with different feel and sound. The high spherical keycaps are exactly what I like (using SA profile on Cherrys, normally) so it wasn't hard to adjust and that's the reason this is my easy choice among boards with Topre switches.
Of all the keyboards I own this feels like the most high quality, a very solid and heavy product. I think it is worth the money, but if it is for you or not I don't know - I would have liked to be able to try before buying but happy I took the risk.
As for this deal, hmm. Free headphones to compensate for long shipping delays...