The CUBE weighs in at just over 2 pounds, and is smaller in stature than the smaller of the 405/410. IOW it is a *LOT* smaller than the larger one.
Anyway, that aside, there is ZERO slop anywhere in the CUBE system, including the gear drive, even with the friction dials set to minimum. The biggest difference here is the CUBE is a rack-and-pinion drive while the 405/410's are worm drive -- and worm drive designs have inherently more gear slop. Comparing them directly is like comparing the driving experiences between a Mercedes and a Chevy on the Coast Highway to one-another. So yes, they both get you there, but one does it with a lot more class, comfort and convenience.
Final comment: I have never heard of anybody selling one of these because they didn't like it. Moreover, the fact you rarely see these for sale used (like one per year across all of the boards, eBay and Craig's list combined) I think is a good indicator of customer satisfaction.
Final, final comment to Marc and Don: I know you guys well enough to simply say, "Trust me, hold your breath, pucker up your pucker string and part with the cash for one and get it over with. Two minutes after you have fiddled with it with it on top of your tripod and your camera on top of it, you won't ever look back!"
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