Tim,
No offense, but you're tilting at windmills. The RRS screw clamp is a Quick-Turn affair, so a quarter turn open, reorient your camera, quarter twist and locked. You know it's tight because it wont turn in any further... In use i't's far faster than the Arca lever as you don't have the lock pin to fuss with.
As for the RRS lever, it may be a few 100ths of a second faster, but I have seen a few cameras dropped because of that clamp opening unexpectedly --- and that was because it has no lock pin to hold it shut... One of them was mine, and fortunately it got caught by the hand-strap so disaster was averted. The RRS lever clamp is also NOT adjustable. Works fine with RRS plates, but mount any other brand and it either won't clamp shut or won't lock tight and no way to fix that in the field. At least with the Arca clamp, you can adjust it tighter or looser. Those two reasons together are why I dislike the RRS lever clamp.
PS note on the Arca lever clamp: While I generally still prefer the RRS screw clamp, the Arca lever is okay since I only need it to hold my rail. However, I have modified it to function better for my uses. If you take it apart -- yes, unscrew it until the lever comes off -- you can file a flat at the 90 degree mid opening point; a diamond fingernail file works great and you want to take it down about half to a full mm. This allows the jaws of the clamp to open a bit more -- meaning you can tighten the lock further on the shut position and now allow the rail to slide, but not come out of the clamp at the half-way open point. Then the secondary opening position, and you can pop the rail right out the top. In use, this may be slightly more convenient than replacing it with RRS screw, as long as you use the a sliding rail of some sort with a screw clamp mounted.
PPS on sand: The Cube is a very "open" design, meaning you can easily get to the inner guts without disassembly to clean it. Moreover, I lube mine with paraffin candle wax which isn't sticky. Bottom line, drop it in the sand and for the most part, you can blow it clean with your mouth. Wet sand will need canned air, and any salt water, I'd rinse it under the shower with HOT fresh water and then blow it dry, finally re-lubing with a candle.
Cheers,
