Gents I have been asked to comment as I have built both kits - virtually simultaneously.
The ZM kit is as you might expect are far more demanding build and getting all the separate panels to align will take care. I still think they should offer a traditional full half fuselage moulding for anyone who does not want to open the whole thing up.
Revells kit can be thrown together but is riddled with errors omissions and inaccuracies. Its a long list but for me the biggest problem is the shape of the nose which is considerably fatter and more bulbous than ZM - once you see the two side by side you can see how wrong it is. In isolation it can look presentable. The cockpit is lacking a lot of detail and I ended up replacing both seats on mine. The nacelles are at the wrong angle on the wing and all the filler ports are moulded backwards. There is also a poorly designed joint line right across several small hatches which cuases nothing but grief! There is some banding on the lower fuselage and the tails skid bump is the wrong shape - oh and the prop blades are mishapen. Undercarrige has been modelled unloaded so has to be adapted.
ZM on top and Revell below
Comparison of the two windscreens - the ZM version on the right is the test shot and not the new one but its shows something is very different! Close up also of the Revell nose - lacking the taper of ZMs
ZMs kit is just far more accurate! The cockpit is good to go right from the box and of course it has all that engine detail etc that Revell dont provide. For me the Revell kit misses the mark in terms of capturing the look of the UHU - ZM would be my choice because it has that distinctive nose - for me thats what the UHU is all about!
AIR Modeller Magazine