Can't speak to the keyboards you've listed, but this company
manufactures high quality buckling-spring keyboards, based on the IBM M standard.
Most actual typists *much* prefer a mechanical action. If you hunt and peck, or don't do extended typing, it might make less of a difference. Well-made mechanical keyboards can also last for many, many years.
I have three of these Filco's with Cherry Brown switches: http://www.amazon.com/Filco-Majestouch-2-Tenkeyless-FKBN87M-EB2/dp/B004WOF7QM/ref=sr_1_1?s =electronics&ie=UTF8&qid=1345516017&sr=1-1 . If you want speed and feel, with reasonable quietness the Brown switches are great. The Blue switches are supposed to have a bit more feel, but they are a bit louder.
I used Microsoft Natural keyboards for years. They would last a year or two, but they would then be so mushy and sticky that they were useless. I would never go back to the old cheesy keyboards. They are junk, regardless of brand. (In my ever-so-modest opinion, of course! )
If you mostly type text consider an 87 key version like mine and then use a 10 Key pad for those times you need to enter a lot of numbers and/or for gaming: http://www.amazon.com/Filco-Majestouch-TenKeyPad-Tactile-Numberpad/dp/B000MGBPNI/ref=sr_1_ 19?s=electronics&ie=UTF8&qid=1345516017&sr=1-19 You would be amazed how much less keyboard to mouse movement you'll need with an 87 key keyboard versus the standard 105 key keyboard. With a Filco, you have the choice. I don't think many other brands offer 87 key keyboards.
I have one of the 10 Key pads that I thought I would use. I'm not a gamer and do very little data entry, but I type at least ten hours per day (I'm a software develper). It only took me a few hours of use to get used to typing using the number keys at the top of the keyboard. So I've only used it about twice.
Consider getting a keyboard rest: http://www.amazon.com/Filco-Leather-Wristrest-Compact-Keyboards/dp/B001EY9RJQ/ref=sr_1_12? s=electronics&ie=UTF8&qid=1345516017&sr=1-12 They come in 105 key and 87 key sizes.
p.s. The only downside of mechanical keyboards is that they are not water resistant. You have to keep them dry. To me that's a minor issue.
Thanks for the reply dan that was very helpful.