Answer to the question - apparently the ones that aren't in my collection, as I seem to be unable to stop buying!
In all honesty, bats from different regions offer different qualities. Huge number of things which affect this, which will be a mixture of different techniques and also conditions. (Bats from Pakistan, Australia and India always seem huge because it's drier there, and so the clefts naturally lose more moisture) Personally I've gotten on best with Indian bats. Light and really ping. In terms of the best for longevity and consistency, I'd most likely buy English/NZ(Laver).
Thing is, a lot of these are perceptions based on what I've used, and I haven't used many English made bats that I've thought, 'phwoar, what a cracker' that are 2.9 and below, while Asian bats tend to offer more forgiveness at lower weights. Just my own experience, please don't shoot me!
That being said, around the weights of 2.10-2.11, a lot of English made bats I've had really feel exceptional. This might just be my own tendency to buy bats above 2.9, but perhaps that's also down to my own experience with most lighter bats not quite offering the punch I want. (Have relatively quick hands, but not a big hitter)