@Romet.Lyytsepp Thanks! I've waited a long time to get one with such features. The most noticeable improvement is in sharpness - with no Optical Low-Pass filter on the sensor, images are much sharper, requiring very little sharpening in post. I think the color rendition is good, with more settable options. The file sizes are huge, yes, but not a major problem with a decent computer processor and SSD drives for rapid throughput and storage. Of course, huge files are not needed for internet postings, so any large file may be reduced somewhat for that purpose (retaining a large original for printing purposes). You should splurge and get one!
@Romet.Lyytsepp Yes, they should drop in price a bit when the replacement is announced (D880, perhaps) this Spring. D850 was on sale in December for $500 off, and sold out everywhere in a week. And yes, the D750 is still very good.