I had a Unicomp die on me last year -- after ~9 years in service, so it didn't owe me anything.
I've owned three. First one was PS/2 and had no Windows key, but I fell back in love with the Model M style for the time I used it, so when PS/2 stopped really being a thing, I got a second one with USB and a Windows key. It gave me good service for many years until it fell victim to a beverage incident. Ordered a third one right away, but it had an intermittent sticky/repeating key on arrival. Not that they wouldn't have exchanged it for me, and whatever it was sort of worked its way out over time, I still have it, but it was kind of a trigger to see what else was out there.
Much to my surprise, mechanical keyboards seem to be making a come-back.
Indeed they are. If you look into it, the popular thing is the variety of
Cherry MX switches named by color, that give different typing behaviors and feels. Great stuff, great feel, very very good rep. I think they're even serviceable/replaceable, not sure. Also they're German, if you're into that sort of thing.
Lots of keyboard manufacturers have been incorporating them, to the point it's become almost a defacto vocabulary for expressing a keyboard's feel, its tactile response.
Think of it like... you probably don't buy shoes on Amazon, right? You can see them fine, but you need to try them on and see how they feel and walk in them a bit before buying. Same for keyboards. It's a personal decision of taste and comfort in a tool you use all day every day, and the type of guy who has a Unicomp keyboard is a guy who's particular about his keyboard. So either you had to buy in person, touch and feel first, or kind of guess and hope online. But now the gaming keyboard vendors tell you "We use Cherry MX switches, choose from [Blue|Brown|Green]" and then you're like "Oh, I've typed on Cherry MX Blue and I know how that feels", or at least you may have read reviews and have a sense of what you're looking for, so it actually helps the decision process quite a lot.
The Cherry MX Blue are known for being a very Model M like feel and sound. If you're a Unicomp guy, you'll feel at home with these. It's got that trademark buckling spring sort of action, nice long travel and the progressive resistance until you hit that breakover point, and of course it's loud AF. Not having them both in front of me at the moment to A/B test, I'd say it's got about the same travel, maybe 10-20% less on resistance and sound level. I still love my Unicomp, but if you put a gun to my head and made me pick right now, I think I'd take the Cherry MX Blue purely because it's just a tiny bit less fatiguing if you're doing truly constant typing all day.
Anyway, what makes Das Keyboard worth $70 more than a Unicomp?
The built-in two-port USB 3.0 hub appealed to me. I've designed my workspace so I have a lot of free space around me, both the work surface and underneath so I can swivel my chair around freely to other tasks and devices around me. My PC is several feet away from my keyboard and monitor with extended cabling and a hidden USB hub to connect things. It works for me, except I did have to get out of my chair on the occasions I wanted to plug in a USB this-or-that device. Now I can just stick it right in the back of my keyboard.
The media controls also appealed to me. I get a lot of use from the dedicated hardware volume and mute controls. There's a few ways of doing that (programmable wheel on my mouse, or a knob on powered speakers, etc) but long story short, having it on the keyboard worked for my various use cases. I get some use out of the hardware play/pause/track buttons as well. I sometimes play music while I'm working, and it's nice to not have to hunt down the right tab or window if I need to pause real quick for a phone call. I'm not sure how the character mapping works, but things like Spotify and other Windows media apps, including Chrome if media is playing (Youtube, Google Play Music) seem to tie into the modern Windows 10 native media API when they're active, and the keyboard keys do their thing with whichever app is foreground on that API, no setup or drivers or anything, just seems to work.
Das Keyboard make a variant with RGB lighting, but I don't have it, I didn't really see the value in it. Others may get some value, and that's fine for them.
The one reasonably priced exception I found was the
Logitech K840 so I ordered one. The keys actually have a pretty decent feel to them, but I couldn't get used to the totally different form-factor of the housing. It turns out the palm of my left hand uses the corner of the keyboard's housing as a spatial frame of reference, and the Ctrl key is a poor substitute for that.
Everyone types a little different just like everyone writes a little different. My typing stance/style is mostly correct from a traditional or official perspective, with one major glitch. I'm screwed if I sit down at a Microsoft Natural Keyboard because I learned to strike "B" with my
right index finger.
I never really felt any positive ergonomic vibes from those things anyway.