Good idea. As you mentioned previously, depreciation on these things is low compared to many other bikes. So the logic of considering a new bike makes sense.Not yet. Still waiting for 2020 so I can compare.
That said, it's likely you'll have just as much fun on a used bike. Maybe one that serves as your "research bike" so you can really figure out what stuff you want to add to your next purchase; a brand spanking new NC 750 X DCT. And since there where some relatively significant changes to the 2018 model, might be another year or so before there are additional real upgrades.
A high quality late model used 700/750 or a brand new bike?? Arguments can be made for either choice. Fun stuff this motorcycle buying!