After playing MGS4/MGO at TGS 2007; Japan, I realized that the DualShock that was present there, replacing the SIXAXIS, was different. No, it's not the weight, yes the sticks are more sensitive and raised, but that's not the main reason for my liking. Let me explain.
In MGS4 (and other games, I'm using shooting in this example), when the enemy shoot at you from a side, say the left side, then the controller vibrates more on the left side. If a car just got blown up, behind you, then the lower part of the controllers vibrates. Basically, the vibration's direction indicates where a certain impact is coming from. In Gran Turismo 5, if a car slam you on the right in a hard shoulder, then, you guessed it, it'll vibrate on the right, with little vibration on the left (mind you, that's pretty handy if your driving with the in-car view, beats having to switch cameras all the time to see where the hit came from).
This version, DS3, is not just another vibrating controller like its predecessors. It's an improved version. It's slightly heavier than the DS2 (the PS2's), but that's much better than the SIXAXIS, which feels like those remote controlled plastic cars controllers; light and could break easily.
The motion control is still there, for anyone who still likes that feature. But it's better to have both. This is a must buy for anyone looking to purchase a PS3 as only the MGS4/80GB PS3 bundle is confirmed to have the DS3 controller with it. All other PS3 packages/bundles will have the SIXAXIS instead, so you can see why it's a must purchase.
BTW; there's no region lock on this, so you can basically import this from import sites and still use them (playasia.com has ceased distribution in EU territories mind you).