I disagree. Every Microsoft Natural keyboard I've used that's more than a few years old has gotten incredibly mushy. I make an exception for the original line of Natural Keyboards in the mid-1990s that had a firmer membrane, but the current range, including the "Ergonomic Keyboard 4000" just feels like I'm typing on kitchen sponges.
Sad to hear that. I like the 4000, in fact I am typing on one right now.
I vaguely remember Fujitsu had an ergonomic keyboard (one could even adjust the angle between the two halves), but I have never laid hands on it, so I cannot say anything about the quality. All Fujitsu notebooks I have touched had absolutely crappy keyboards, but that might not mean much.
I've never had a 4000 that survived more than a couple of years. Inevitably one of the keys gives out, and then it's off to Office Depot to buy another one.
The main thing it's got going for it is the overall layout, which is fantastic. If someone made a keyboard using mechanical switches with the same layout I'd snap it up in a hot second. But for reasons unknown, while keyboards with mechanical switches have proliferated in recent years, none of them incorporate 4000-style ergonomic features like split keys or a curved key bed.
