I really got used to my new keyboard and a bit bored of the original version in use now at work. So I decided to do something good for me and by another one. I'll take that on work on monday…
I bought it privately because I can't convince my colleages why I need a special keyboard! But I'm really used to ergonomic keyboards now and it's more fun writing on them. Further I rather often suffer from some kinds of RSS (repetitive stress syndrome) and a good keyboard helps.
So why not use the old one longer? First the feeling is very different to the new one. You have to press the keys much harder on the old one and some even start to stick a bit (maybe greasing could help). And the new ones is more ergonomic too (the wrist rest of the oringial natural keyboard is very steep and too narrow).
All in all I'm very pleased with the Natural Ergonomic Keyboard 4000. I'm sure there're better keyboards out there, but most are much more expensive and many of them are not available with a German layout…