I work in IT. I type. Constantly. I'm also a young Generation X so I took a typing class in 7th grade. I touch type. And since I do it for a living I do it relatively quickly. It's part of my livelihood. I spend a lot of time every single day on a keyboard, so a good one is a necessity for me. I was a big fan of the Microsoft Natural 4000. I bought at least 3 or 4 of those things in the last decade. One would break, and I'd just buy another. Well, they cost about $300-$400 now so that's no longer economical at all. I figured it was time to try the next iteration. I researched and researched. I tried the Surface keyboard. Didn't like it. I tried the "sculpt" keyboard...also didn't like it. I used the macros and key assignments with my old keyboard, and I use them a lot so I was looking for a keyboard I could continue to do that with. The LXM-00004 does that. In fact, everything translated in the software.Typing Differences:The F6 button moved to the left hand side of the split.The C, X, and V keys for someone hit differently now. I'm not sure why. If it's their angle or what, but I made some mistakes the first week with those, till my hands adjusted.The backspace button is smaller. Not so small that I miss it when I reach for it, but it is smaller.The arrow keys are bigger. Again, not so big it throws me off, but it's noticeable.Smaller Windows key. I use Win+R, Win+X, Win+E, Win+V, I used to use Win+Shift+S and Win+. (more on that later) and they resized or slightly shifted placement of the Windows key (or both), so after having spent so many years on the 4000, I do occasionally miss it when I reach for it. I'll get used to it, but that's probably my biggest typing related complaint about the redesign.Number lock was moved from the top row of the number pad to the top row of the center column. So it sits above PgUp on this keyboard, which seems odd and unintuitive to me, but it has a tiny light on the key itself to indicate if it's on or not.Feature Differences:You can read about most of these in the keyboard specs, but there's only 3 fully programmable numbered hotkeys now instead of 5 on the old 4000. However you get a dedicated screen capture button. Which was not raved about enough in this device's marketing and was one of the things I used to build a macro to do for the programmable keys - now I get it built in!All the usual media keys for volume and playback, a task view button and a dedicated lock button, which I'm training myself to use. The handy volume up/down/mute keys are all still there, albeit in different spots.Yes, there's also an "office" button. I could've done without this. I never use it. Or at least haven't used it yet after a month of owning it. And they shrunk the Windows button to make room for it.The emoji button...OK, that's kinda fun, I'll admit. It just brings up the little fly-out menu that the Windows key + the period key (.) used to, and still does, only now you have a dedicated button for it so it's no longer a cool sneaky cheatcode that hardly anyone knew about.All the functionality for programming buttons is still there in the Microsoft Mouse & Keyboard Center. I highly recommend leveraging this software if you buy any keyboard with macro/programmable functionality. You can reprogram the media keys if you feel the need to but not the "Application" button, although you can disable it. And you can turn the emoji key into a right side application key if you'd prefer to do that, but those are its only options. There's also a dedicated search button (I never use) and a calculator button (which I do use).The middle column buttons are for the most part identical. Home, Delete, End, etc, all in the same spot.There were things about the 4000 I never used. The Zoom scroll in the middle of the keyboard, was something I never used and isn't on the LXM-00004. Same with the "My Favorites" button, the Web/Home and Mail buttons on the top left of the 4000....I never used any of those ever, so they did cut some of the fluff from this one in actually beneficial ways too. Overall it's the first new ergonomic keyboard since 2005 that I don't hate.