Hi
It is interesting to note that a .22 bullet has burned all of its powder in the first 18-19 inches of the barrel, which means that the rest of a .22 barrel should be doing little more than slowing down the bullet - but I so want one of these Super Exclusive models (not available over here - at least no one knows about them for ordering purposes)!
No sense in talking science to a CZ fanatic, ay? 
Wish they made them with AA or AAA grade Walnut instead of the Beech though. Might have to buy one and get the stock made! 
I think the oft quoted line about rimfires achieving their highest velocities in carbine length barrels (16 to 18 inches) is an urban legend. Check out this test we ran at my club:
We conducted our barrel length vs velocity test on March 21, 2009 at the North Alabama Shooting Association range in Sheffield, Alabama.
We used five CZ 452 .22 rifles with different barrel lengths and fired six rounds each of six different cartridge types. The chart below reflects the average velocity of the six rounds followed by the standard deviation of the six rounds.
The rifles were:
CZ 452 Ultra Lux with a 28.6" barrel
CZ 452 Special with a 24.8" barrel
CZ 452 American with a 22.5" barrel
CZ 452 FS with a 20.7" barrel
CZ 452 Classic with a 16.5" barrel (Fuzzy the Limey's old CMP Sporter rifle)
The cartridges were:
CB Longs = CB
RWS Subsonic Hollow Points = SSHP
Wolf Match Target = Standard Velocity or SV
American Eagle Solids = Lead High Velocity or LHV
CCI Mini Mag Solids = Plated High Velocity or PHV
CCI Stingers = Hyper Velocity or HypVel
-------CB------SSHP----SV-----LHV------PHV----HypVel
28.6 652/53 968/16 1037/13 1206/16 1188/24 1660/50
24.8 676/34 997/20 1062/13 1219/22 1217/40 1660/47
22.5 653/65 998/08 1069/10 1229/22 1213/24 1708/31
20.7 701/44 957/39 1062/05 1224/14 1190/11 1661/26
16.5 685/22 949/27 1057/14 1205/17 1208/22 1666/39
