It is unlikely that dust or dirt will slow you down. The joints are sealed. If you do have any problems like that - send it back and get a brand new one. No charge. It is designed to deal with some nasty abuse. ;-)
Hey Carlos..I'm having a bit of an issue locking the extension arm. In this video (2.11) https://vimeo.com/50730830 it shows how easy it is to move and lock. However My unit is configured that the "lift and release" side of the safety is pointed towards the locking mechanism. Basically the release safety is located right between the notches on the locking mechanism. In ur video its the reverse. Because of this (i think ) I'm having quite a hard time sometimes locking and unlocking. Is there a way to reverse the direction of this safety release so they both don't conflict with each other? right now I have to lift and release while turning the locking mechanism for it to move (because they basically overlap each other). Hope i'm clear enough in this description. You may be able to see what i'm talking about here in the 2nd pic http://www.bmcuser.com/showthread.php?2008-Solid-Camera-EVF-mount
However I could just not be doing it right ...I duno
edit: I'm seeing now that my safety release is a bit different than the one in the vid. The one in the vid does not have the "lock" and "unlock" sign, mine does. ( In the vid those signs are actually on the locking part and not the safety release). So I guess my version BOTH locks (and unlocks) and is also a safety release I suspect. Still I'm having difficulty sometimes locking and unlocking it...is there a specific way to do this?