OK, so I've had the Mankati on my bench for a week now. First let me say the framework and mechanicals are about as robust as you'll find on a consumer 3D printer, you would actually have to try rather hard to break 98% of the printer. I think there's a lot of potential in this machine, unfortunately like 99.9% of the consumer machines on the market it has it's share of warts and while it can print right out of the box, don't expect great quality prints.
The major downfall of this printer are the hotends, by the far the absolute worst I've ever had the displeasure of using. I have yet to start or complete a print of any size without having to deal with clogging or failure to start feeding at all. That's beyond the fact that one was roughly 1mm lower than the other so the first time I tried to print anything it was dragging the nozzle of the lower head through the filament that it had just laid down. To even get to the point where I could get a reasonable print using one nozzle I had to disassemble the dual hotends and shorten one of the peek barrels to get them to match heights, there is no mechanism to adjust the height of either in the as-built configuration, a must IMO if you're going to have dual heads.
The other issue with the hotends is the factory supplied fan shrouds have two outlets, the top one aimed at the peek barrels and the lower at the print bed. Normally this would be a nice feature IF the second fan didn't run all the time with no way to turn it off, the crap peek used in the hotends requires cooling 100% of the time they're heated lest they become puddles on the printbed. If you use PLA exclusively it's not that big of an annoyance but it makes printing with ABS impossible as the print is cooling and starting to lift before you get 10 layers down on the printbed. A couple hours redesigning and printing new fan shrouds so they only blow over the hotend barrels fixed the problem of not being able to use ABS, probably could have gotten away with just changing the one on the fan that runs all the time and left the other for cooling PLA prints though I rarely print anything in PLA that needs to be cooled while printing so keeping the two barrels cool seemed like a better use of both fans.
The other thing that really doesn't get high marks from me is the fact the printer uses an Arduino based board and presumably a modified version of Marlin firmware but not any version that is open source as far as I can tell, you get the firmware in hex file format from Mankati and forget about being able to make changes. Since the base printer is essentially an Ultimaker clone it can be run on the Ultimaker 2 version of Marlin if you know enough about what you're doing to make the necessary changes to suit the Mankati.
It also uses a Mankati specific version of Cura and having spent a year with Repetier Host and Slicer I'm not loving the supplied interface, doesn't have quite the same configurability that I get from my SD3 and Rostock Max on R/H and Slicer. I did try running a print that had been processed with Slicer and it does work, just need to spend some time figuring out the proper setup for the Fullscale to make it work right.
So overall it is a well built printer and doesn't suffer from any of the mechanical issues I dealt with on my SD3 in its first weeks. The hotend problem is being taken care of as I type, a pair of E3D V6 hotends on the bench and an adaptor to mount them to the Mankati printing on the SD3. The software thing is minor as far as I'm concerned, the hotends are the bigger problem and I think once that's taken care of this is going to be a really good printer.