Purchased the kit from China back in 2014. Cost was around £320 (including customs duty) and included 2 x 1Kgm rolls of filament. It was based on Prusa i3 but had an acrylic frame, not aluminium as the later ones moved to and it did not have auto levelling. The Z axis did have two motors with 'built in' lead screws (supposedly better than lead screws that are clamped onto the spindle). Kit was easy to put together and doing this gave me a good intro to how it all works. It also worked straight away! Have used it to print a few useful objects as well as many 'frivolous' ones.
Overall it was a good buy at the time. But now I am looking to do some more intense/precise printing and I realise ideally it needs better calibrating, larger prints have the habit of warping, the Z axis motors started 'skipping' (and finally jammed) and ideally one needs auto bed levelling. However, so far I have been able to correct the jammed motors (stripped down and gunk removed from threads and inside motor) and am planning to build a simple enclosure (to get more stable temperature to hopefully reduce warping) and to add auto levelling. Also need to perhaps straighten the Z axis lead screws as these may cause some skips plus see if the nema 17s should/could be plugged in to two connectors (the board has an extra E1 socket that Marlin could make a Z2 socket). Again this is proving to be an interesting learning experience.
I did print and install two filament guides. One allows filament to loop to top of machine then down to extruder and reduces any strain on filament when executing fast moves (occasionally I had filament breaks). The other sits in extruder and allows the use of flexible filament. Also printed some cabling bracketsto tidy up the runs and some 'hold down' brackets to screw printer and filament holder onto a base board.
Pros: Price; Good Quality; Instructive; Lots of data on web; a few spares provided and mostly commonly used parts that are easy and inexpensive to source.
Cons: Lead screws slightly warped; No data for Arduino board used (so will be making a guess).
One other positive for me is that it has got me interested in all aspects of Arduinos, 3D design, general CNCs, and even programming in Python. All good to keep the brain ticking over!