I have been using the Cube Pro Duo 3d printer for 2 years, and everything i write below is from my personal experience. I used both PLA and ABS filament.
The software is easy to use, and i found everything in the help menu i needed at the start.
The hardware is good quality, looks good, and is safe, since it has a full body which can be opened quite easily for maintenance. The bed can be removed for removing the print easily.
The quality of the prints are really not bad, the built in support generator works okay, and overall i'm satisfied with the prints (after a bit of tinkering with the settings).
The firs limitation is in the software. I sometimes print very complex projects and due to this i was able to find the limitations of the software quite early. Sometimes the software crashes, other times it doesn't built the whole thing (multiple layers are missing from the top), and the file transfer over wifi is hideously slow (sometimes over 50 minutes for a 20 hour print), and if you don't have enough material it only shows this after you sent it over, and once you change the cartridge you have to resend the file again.
The mechanism that holds the bed in place(a big metal ring and two magnets) doesn't always locks the bed in the correct position right away and you can't tell this by eye, only when the print is done, and then you can see when the bed shifted to it's correct position by the slight shift in the print itself. And the cartridge chip reader pins broke off after 3 months. the filament loading system is rubbish, nine out of ten times i got a filament error, i tried everything, but it just doesn't work. When i change the filament it sometimes get stuck, and i have to remove a few pieces to clean it out, this isn't the problem, it happens, the problem is that i have to remove the heating jet for this procedure, and it has a heat sensor on it, which has the most brittle wire on earth. I managed to only break two of it in the last two years, and if i solder the two wires together the head starts working, but after 93 minutes of printing t just stops with a heat error.
The prints are basically good, but the small details are hard to recognize (sometimes it tries to make them, but just messes up the print), if the supports are close to the vertical-ish surface of the print, they literary need to be cut off, because he machine sticks them too close to the surface and they stick together pretty hardly.
The "sense how much filament is left" part sound good, but is achieved by a chip thats built into the filament cartridge. With the "special made" Cubify cartridges it works well, BUT it means that you can only use the Cubify Cube Pro branded filaments. You can't use any third party filament(unless you stick the chip into the machine and load a different filament into the nozzle, but then you end up with a spool of filament that you can't use in this machine). It wont print if you don't have a chip in it, and if it doesn't have enough material on it. And the Cubify filament is low quality and 2-3 times more expensive than the other much higher quality ones.