This review presents my rating of the main model. I would like to mention that I primarily bought to stock up on green parts and to get a large pneumatic cylinder for my 42053 Excavator. (The boom of it needs an upgrade because is has become too heavy.) Therefore please expect a very biased review.

This is what you will get:

(The box is on the left underneath).
The size (area) of the box is 80% of that from sets 42025 and 42066 which is proportional to their respective piece counts.

The main model, it's new parts, and the building process have been described in detail by Huw's review.

I believe the colourful composition is owned to the strategy that any parts will be provided perferably in a single colour and that parts of similar shage, e.g. beams with +/- 2 holes must have different colour. I wouldn't have chosen green beams to be used in the chassis.

Rating

I would like to focus on the functions and their playability of the model:

Steering is achieved by a large turntable between front and rear pair of axles plus linked turning of the first = front axle. It is very responsive. However, especially on flat surfaces you will notice considerable resistance when steering is changed between left and right turns. I believe is happens because on the front axle you not only change the orientation of the wheels but is is also necessary to displace them perpendicular to the direction of motion.

This set is equipped with an electrical driven compressor to supply pneumatics with air. So you don't have to pump manually while handling the logs. The rear part of the vehicle is dedicated to this.
When to motor is running, this whole unit vibrates because the tube connected to the pump gets in contact with the top cover that resides above the battery box.
Besides that it is working very well. You will hardly notice high load when pressure rises if air is not consumed. (The compressor will also work with a M type motor.)

The main function of the harvester is its arm with the logging claw.
It is raised and lowered by two larger pneumatic cylinders. This works very well. The control of new valves makes it difficult to put back into neutral=middle position. Therefore you often find that the arm is slowly going up or down. I replaced the 20-tooth gears by levers to get better control.

Second pneumatic function is opening and closing of the claw by means of a small cylinder. This does not work very well. To me it seems that leverage is not optimal.

Cutting of trees is implied by a large sawing blade. It rotates freely and is mounted to a small beam. It swings in back position when the arm is raised. It may rest there until the arm is down again and the swing into cutting position is triggered by closing the claw.

The whole cutting head can be rotated by hand from vertical to horizontal position. However, I think there is little reason to do so.

Real harvester can push or pull tree logs a) to remove small branches and b) trim to fixed length pieces using the saw. This would not be possible with this model because the spiked round 2x2 bricks that indicate this function are mounted in wrong orientation.

I did a modification to mine to get a more realistic appearance:

(Additional yellow parts serve as hazard warning indicator.) The "tree logs" provided with the set are fixed by the four rubber pieces.

The cabin with arm can be rotated by 270..300° again by hand without any transmission involved. It sets the harvester nearly off balance if oriented perpendicular to the chassis.

There is plenty of equippment in this set such as chainsaw, small log and sawbuck, a tool box, cup and thermos flask, chains. However, there is no actor/figure that would operate them.

Comparison

In the headline I suggested comparison with log loader 8443. Its main functions are similar: Grab and lift logs and articulated steering. All that was achieved by a mere 327 parts, e.g. less than a third of this set.

Reasons to buy (nonetheless)

- green liftarms and panels

- metallic wheel rims. I will try these on the 42078 Mack.

- large pneumatic cylinders. I need one to upgrade the boom of my which has become too heavy for only one of these.

- if you think the ZEUX is just another, but BIG loader.