The other reviews echo my thoughts as well on this great little mount.

I bought this mount to use as a portable lightweight mount for Solar (& Lunar) viewing in Ha and whitelight.
I am mounting an ED80 on the Mount Zero set on a heavy duty Manfrotto carbon fibre tripod and find this to be more than adequate for my needs. I did test it with a 120mm scope (6.8kg) and found it perfectly usable but much more affected by wind or the slightest knocks.

I made a slight adjustment to the azimuth axis to remove slight backlash and it’s now very smooth and responsive.

It is expensive but well worth it as for me, it fits my needs perfectly.
The only issue I have is the manual currently it is only in Japanese although, it’s pretty straight forward to setup without the manual.
Note: You can get a decent translation the manual using google translate where you can upload the pdf

6 may 22
A step up from my SW az 3/4 & vixen porta mk1 that I've owned (I did like the vixen)
Alex's review above is spot on,
Work great with SW 102mm mak and ES 70mm angled binos,
Using a manfrotto 055 (rated at 7kgs payload) & the above optics were fine on it,
Using a altair 80mm edt ( 5kgs)& scopetech 80mm f12.5 (2.2kgs) it took 2 seconds to settle on tapping the scopes.,
Changing to heq5 legs and extention the tap test was 1 second
It did wobble a bit on focusing at 200x using the long scope but no problem,
A suitable motor focuser might be next,
I've gave it 5 stars above but 4.5 it about right
It is very good but not perfect,
Also hats off to FLO again for next day Saturday delivery at at the standard rate charge.
Tony

The Zero promises excellent portability, useful features, and a decent capacity.

I already own the Skywatcher AZ5 but had good reason to believe this would be an upgrade. In practice, it met my high expectations and proved to be an upgrade over the AZ5 in most areas. I primarily compared the mounts on a sturdy carbon fibre tripod, carrying a Vixen SD81S loaded to ~4.5kg.

First, the Zero is solidly made with smooth operation. I often feel that there’s a little play inherent to the AZ5 but the Zero feels precise. The finish is good but not quite premium.

Portability is incredible. While the AZ5 head is only a few hundred grams heavier, it’s harder to assemble in the field and is a larger, more awkward shape. Furthermore, the Zero folds down neatly, clearly showing the thought put into its design.

It is capable of both free movement and slow motion without clutch adjustment. Operation is very smooth, lacking the stiction found in the AZ5. The slow motions take more force to turn than the AZ5 but are smoother.

The capacity of the mount is rated at 7kg. I think it’s fairly accurate. It’s not rock solid and does wobble slightly when focusing but is still a noticeable step up from the AZ5. Stability varies between scope designs but I would say a 100mm refractor is probably the largest I’d be happy to use on the Zero full-time.

The Zero also comes with weaknesses. The clutches can’t be locked. This demands some caution if you like to move your rig in one piece. Balance is critical. Even tightened fully, the gears can rotate, and your scope will swing down if unbalanced. Like the AZ5, slow motion will not work if balance is too far off.

Finally, the price. While it competes in capacity with the AZ5 and Porta II, its price is a level above. Even the Japanese price of ~35,000yen is fairly expensive. The same money can get you a Stellarvue M2C for example. That mount is rated for a much greater capacity but gives up the slow motion. For its price, I would recommend the Zero to those who know their needs well.

Advantages: extremely portable, well built, decent capacity, offers slow motion controls.
Disadvantages: high price in its class, clutches cannot be locked and balance is extremely important.