Microsoft Natural Ergonomic Keyboard 4000

I should have paid more attention to the clearly reasoned (and IMHO *accurate*) negative reviews. After about one week of not-very-intense use I had to stop using this apparently well made but horribly designed keyboard. The use of my right hand and arm became painful. There were three main problems: #1 The amount of thumb pressure required to actually register the "space" key was way too much to type with any comfort or confidence. Even if I concentrated on always striking the space key so that a space would be inserted into the text or computer code where needed, I found that about 1-in-12 or 1-in-14 attempted spaces would not be inserted. It is terrible that part of one's brain must focus on striking the space key with heavy force; it is even worse that one must proof read each page of text or code to ensure that spaces have been inserted where needed. #2 The space key is intrinsically badly designed anyway, because one wants this key to be equally welcoming to both the left and right thumbs. It isn't. I found that my right thumb worked best, requiring unnatural contortions to ensure spaces were inserted where needed. #3 In general, I found that the $10 keyboard Dell included with my latest XPS desktop requires a more comfortable amount of force for ALL of the keys, not just the space key. This could be because the Microsoft Ergonomic Keyboard 4000 for Business requires greater downward movement of the keys for a stroke to be registered. Problems #1 and #2 are so severe that I found this keyboard simply unusable. This is quite an indictment for a way-above-average-cost keyboard that is allegedly designed and built with proper ergonomics in mind. I am astounded that so many users find this a comfortable keyboard. By the way, during more than half of my PC and computer keyboard use, which dates back to the late 1970s, I have actually used (and preferred) Logitech and especially Microsoft ergonomic keyboards. This is the first ergonomic keyboard I have ever used that I have found to be a thinly disguised implement of torture for thumb, hand, and arm. I now have some appreciation for the feelings of the other one-star and two-star reviewers when they read the patronizing remarks of the many keyboarders who find this device comfortable. Some seem to pooh-pooh (usually in patronizing terms) those of us who find this one of the most wretched keyboards we have ever encountered. It is a little hard to believe we sufferers happened to receive slightly defective devices. The complaint I offer can be found too often in the reviews for our complaint to occur as a result of a minor or rare manufacturing defect. On the plus side, the build quality appears to be terrific.