Well if you found the 5500 keyboard to be tiny, I am sorry, the 6000 keyboard is the same size, except that the keys are more raised and there is a better tactile feel to it.
No comparing the C7xxx keyboard with the 6000 or the 5500 series. They are entirely different.
But even then, I first used a 5000D keyboard and used to compose larger emails etc , then moved to the C750 keyboard. I composed the same larger emails - but it was definitely faster and easier on the fingers to type than the earler experience.
Now having moved back to the 6000L keyboard, I take more time in composing the mails, but my fingers are slender enought to accomodate easily on the smaller keyboard. But of course the C7xxx keyboard is easier to type on than this.
The other point is that I haven't found any key that I miss on the 6000L that was there on the 750, except the shortcut keys and the two shifts and control keys and all that.