Just looking for some opinions as to which camo patterns (on a weapon) are most effective in an urban setting, both pre and post disrupted (read that demolished).

There are pattern/color combo's like the "urban" or "urban tigerstripe" from Duracote's website, or the naval type camo referred to as "Dazzle". Prominent from 1910 to 1945, it consists of geometric shapes or stripe patterns intended not so much to hide, as to confuse. I have seen a few weapons done in this style, in colors of concrete and rust with dark accents, and it appears to have merit.
See the photos on these links for examples:

http://news.usni.org/2013/03/01/camouflaged-ships-an-illustrated-history

http://www.shipcamouflage.com/development_of_naval_camouflage.htm

http://www.lauerweaponry.com/index.cfm?fuseaction=category.display&category_id=1067

Or perhaps a do-all like Multi-cam still dominates?

Forget paint.  It won't work.  Do what the WWII Russian snipers used to do:  Hang some fuzzy material  on the forend.  Take a lesson from the Rhodesian Rangers, too.  Don't ever (visibly) carry or hold your rifle vertical.  Why?  Because the human eye finds it very easy to spot vertical lines - Even in an urban environment.  FerFAL use to offer opinions on carrying a long arm:  The gist of it is that the better you hide it the less likely you'll appear to be as a, 'target-of-opportunity' to the other guys.  How do you hide a long arm?  Sling your modern carbine under an arm, and carry it against your body.

Someone in the refinishing forum did an "urban splatter"...looked like it might be pretty effective in the concrete jungle.

Searching for it...

The British Berlin Brigade had an urban vehicle camo that looked fairly effective in the photos I've seen.
It was basically a 3-color/colour camo composed of large rectangles and squares of dark grey or ochre, very light grey or white, and a blue grey.  
Not quite dazzle, not quite digital.

Examples:
BBB urban camo
BBB urban camo2

Good points, Ravenu. I notice all the "tiger stripe" patterns run from low/muzzle to high/buttstock. It would appear more natural (that is, striped vertically, the way things grow, usually) when you carry the weapon at muzzle down port arms.

PigBat, that pattern reminds me of the Dual-tex pattern U.S. Armor experimented with about '78 or so.

http://camopedia.org/images/thumb/8/8c/Usa42.jpg/200px-Usa42.jpg

Circa 1977 or 1978, the 2nd Armored Cavalry Regiment (US Army in Europe) tested a Dual Texture (aka Dual-Tex) camouflage pattern for Military Operations in Urban Terrain (MOUT). This design was painted on helicopters and vehicles of that unit. Following a request from the US Army Training and Doctrine Command (TRADOC), Natick Labs developed a version of the pattern for printing on fabric and test uniforms were also produced. Although apparently effective, this early Dual-Tex pattern was never adopted as its appearance was reputedly unpopular with servicemen.

2nd post.

A UK Company called CROPS makes an interesting urban pattern.