I'm not very sure about their details, and in general I think the idea of an extruded frame is excellent, but here are a few concerns and thoughts (mostly ideas from discussion with some people):
Bed leveling - This is really crucial for delta printing movement and I don't seem to see any sort of leveling or leveling sensors for the bed. This is made more concerning when the bed presumably is removable and soft.
Motors - It seems like they are using DC motors with no feedback (since they mention the extremely low cost, but.. just a guess), and that the motors are on the carriage instead of the frame, instead of belts. Also, this means that the carriages will be heavier, and I suspect that in practice this might result in very low print speeds. Also... I don't see a feed motor on the extrusion head?
Feedback - as mentioned, I can't find any reference of feedback except for 'accelerometer on the head'. This seems like that is the only source of feedback, which will certainly keep costs down, but I fear the accuracy and precision will suffer. Also, ""This same accelerometer is used for auto calibration, plus something even cooler. Tiko can measure its own performance, so with your permission, we can use performance data from your printer to help make every Tiko better."" - maybe they are using the accelerometer for feedback and using big data to improve results.
PLA without cooling - they mention PLA extrusion without active cooling (this is not novel, btw). I think that's fine, but what is more concerning is the result of the PLA print without cooling. Or maybe, it just prints very slowly?
Bearings - the delta bearings... look like they would wear out really fast. They mention injection molded? And I don't see how this will hold up to their claimed resolution in any sort of timeframe
Cost - their goals, and price point and timelines are... very optimistic. This has me a bit concerned... but fantastic if true!