In light of the AWB death, I'm going to be building as many evil weapons as possible...money permitting of course. The dissipator style is definitely on my list, however I am a bit confused when it comes to the pros/cons of gasblock placement.
DPMS places their block near the end of the barrel, while Bushmaster and most other manufacturers place a block midway. So which is better?

do a search, this has been covered extensively as of late

Saw many articles on dissy's, but could find nothing referring to the difference in gasblocks.

I didn't see anywhere that I could find that shows where DPMS places the 'functioning gas block'.

Let me sum up all the threads regarding Dissies:

Putting the gas block under the handguards where a carbine length gas block would be sucks because
everybody knows that all 16" ARs with carbine length gas systems jam all the time because they get too much pressure and all the internal parts eventually explode.  Using the front sight as the gas block on a dissy sucks because everyone knows they short stroke all the time until you open up the gas port the correct amount, hopefully not destroying your barrel in the process, and even when you get it right it won't run 100%.

Hope that helps!

Ohhkay, does maybe have a more technical answer?

Have you seen this thread?