Zooker i presume you mean sectorisation?
It's pretty much split as best it can. Geographically ignoring national boundaries, almost all split horizontally as well. Divide it up even more and as 10W said you're only replacing one set of problems with another.
This is an attempt to reduce the frequency loaading. If it can avoid two transmissions per flight per sector it's proably giving 20 seconds more for each one. Take 25 - 30 flights per hour which is a lot for a sector + say FL340 and you free up a lot more thinking time.
Sputnik may know; was this trialled at Bretigny? They can assess the controller workload very accurately by running a series of excercises with a number of variables