The answer is "No". The ZBox 4 stroke uses the clearly inferior "JL Hoot" gearbox. For a frame mount 4 stroke, the Grubee Skyhawk II (or III) is superior without question. The Hoot is known for more noise, weak clutches, weak gears, a non-adjustable mounting plate, no output freewheel and generally worse quality. The engine is decent- same basic engine you can get with the Grubee- no Honda, but not bad.
[edit]- oh yeah, in the Hoot, the keys on the crankshaft and output seem to be made of room temperature cream cheese. Replace them when you first install....or shortly thereafter when they shear....but you will replace them.
The Grubee isn't the "second coming" or anything, but it is better. For now, it is the top of the 4 stroke frame class. There are other designs in development that will probably surpass it, but for now- it's best....and available.