My favorite feature of this MS layout is the oversized Alt/CMD keys. The position of those keys make it a lot easier to hold them down with your thumb.
If you going to be buying a split Ergo keyboard, take into consideration how you use your keyboard most of the time because the split design may actually be worse for you if you spent most of your time with one hand on the keyboard and one hand on the mouse. What may seem like a very natural typing position, may not seem quite so comfortable if you're using your left hand to hit shortcuts most of the time.
I was fine when doing typing tasks, but found the keyboard very awkward and uncomfortable to use if I was doing a lot of Photoshop or work in design programs.
Topre: Realforce 103U Cherry: Filco Majestouch 104 (Brown), Ione Scorpius M10 (Blue)
Buckling Spring: IBM Model M1391401 ALPS: Apple Extended Keyboard II (Cream), ABS M1 (Fukka/Black), MicroConnectors Flavored USB (Black)
Domes: Matias Optimizer, Kensington ComfortType, Microsoft Internet Keyboard
Scissors: Apple Full Sized Aluminum
Pointy Stuff: Razer Imperator, Razer Copperhead, DT225 Trackball, Apple Magic Mouse, Logitech MX1000, Apple Mighty Mouse
Systems: MacPro, MacBook Pro, ASUS eeePC netbook, Dell D600 laptop, a small cluster of Linux Web servers
Displays: Apple Cinema Display 30", Apple Cinema Display 23"
Ergo Devices: Zody Chair, Nightingale CXO, Somaform, Theraball, 3M AKT180LE Keyboard Tray