I've been thinking about this same question for the past few hours. I've had my eye on the K70 for a few months, but a few minor quirks held me back. I didn't like how the top row of keys (particularly the 3 above Insert, Home and Page Up) were placed so low. I need a bit of spacing because I use the Home key alot and was concerned about hitting the wrong key. I also don't like the dual USB cables, it just seems too messy. On the plus side I love the floating key look and volume roller.
I discovered the Das Keyboard brand just today and have been weighing up pros and cons for the last few hours. Ultimately I bought the Das Keyboard Professional 4 Cherry Brown. I love its focussed 'no-fuss' mentality, and importantly the key layout is near identical to my beloved Dell SK8115 (which I think is a optimal keyboard design, only wished it was mechanical). I'm not concerned about backlighting or extra function keys. I just want a traditional keyboard with mechanical keys, superior build and aluminium body. The Das ticked all the right boxes. It has less features than K70, but it had the features that were important to me. Mind you it cost $20 more than the K70, which puts it close to AUD$200 (actually a bit over if postage is included). The 2 USB 3.0 inputs also helped tip it in my favour.
I'm keenly waiting on delivery.