There's one major difference between them - the Quickfire TK has combined the numpad with the arrow keys, PgUp, Del etc., which makes the keyboard quite a bit smaller. If you use the numpad and those keys a lot, you'll get tired of swapping between them with numlock. If you don't, and you could use some more room on your desk, then it's a great solution.
The Quickfire TK also has backlighting of all keys, with various modes to choose from.
I really like my Quickfire TK, though I have the version with Cherry MX Red switches and red backlighting. But you need to consider your numpad usage carefully. If you use it a lot, you'd be better off with another keyboard (be it the Ducky, or the Quickfire Pro which is like the TK but with separate numpad).
Thanks for replying. I like the coolermaster keyboard too, everything about it just looks better built. I'm not too concerned about the numpad since I use a net book which doesn't even have a numpad to begin with. Do you find that your keyboard is a sturdy build? And performs well throughout gaming?