Not absolutely sure about the performance and internal construction differences? but can tell you that the external physical differences are that a 2052 pipe is slightly shorter in length than a 2053. A 2052 is also a "fatter" pipe in that the diameter is slightly larger than a 2053 especially towards the front end which has a larger dome than the 2053.
Ive heard that the 2052 gives more top end power and is not so good on fuel economy but thats usually when matched with a NovaRossi motor. So it may follow that a 2053 is better on fuel economy but not as good on top end power ? I see 2053's are used on the Ninja/GRP Motors and also have seen them on Picco's