What's disappointing is that it's big but adds virtually no extra keys. You can get to a very useful 130-key layout-- a second band of function keys, two more

What's disappointing is that it's big but adds virtually no extra keys. You can get to a very useful 130-key layout-- a second band of function keys, two more columns, and a knob-- by adding only about 5cm on each dimension compared to your typical 104.