I just bought a CTC too..

[Geoff]

Well, long story short.

Saw some cheap CTC dual black box printers on ebay for $599, after already having similar machines I took the gamble.

First, the Cons - because let's just get the bad stuff out of the way first.

On delivery...
Problem 1: Aluminium bed was scratched badly (they refunded me cost of a new bed, so that was OK)
Problem 2: left extruder motor dead/dying - needed to be replaced to even work at all properly, once replaced was OK - at my cost
Problem 3: Left extruder pipe blocked with plastic that would not melt, even at 250c. I had to use a soldering iron at 400c and some pliers to make it soft enough to pull out, which I did LUCKILY. Otherwise... my god, what was that in there, I could not tell you. It was NOT plastic - even the soldering iron barely melted it!!
Problem 4: No bowden cable supplied at all, had to use my own borrowed from other machines
Problem 5: Only 1 spool holder included (and it was 3d printed... the least they could do is print 2!!)
Problem 6: The 4GB SD card supplied is faulty and mid way through any print from an X3G file on it crashes the machine. I tried my own SD cards, they work perfectly - no problems at all. So it's not the machine, just a faulty SD card they supplied
Problem 7: The Bed has massive wobble left to right, I had to secure it with cable ties to stop the Z axis wobbling during print by using cable ties at the top of the Z rods and fixing them to the back of the frame.
Problem 8: - small gripe, Kapton supplied on the bed, besides being scratched through to the plate, was the slippery kind, impossible to print on - not the tactile kapton you buy for printers.
Problem 9: Related to Problem #7, massive layer lines due to small Rods being used in large holes (come on now kids.. grow up..)
They used 8mm rods and they are in 10mm holes in the frame, so the wobble from problem#7 creates problem #9, massive lines in the print from the machine wobbling and knocking the bed back and forth because it's loose. I have had to secure the bed rods with cable ties so they do not wobble anymore.
Problem 10: LCD screen goes garbled half way through prints ALOT.. it does not affect the printing but you have no idea how long it has to go, or your temperatures. It looks like a bad Matrix dream.
BUT - These are problems with MY machine - not yours. You may get one that is just fine. Who knows really. They are a bargain printer at an entry level price - but capable of alot.
Problem 11: Sticky buttons, sticky sticky sticky buttons.. and very slow and delayed compared to its Flashforge counterpart.

Now, the Pros: (I fear there are not as many as the cons, but there are some..)
* It's a Flashforge dual for half the price. Is it as good? well, not really but it's close enough that for the price, you really cannot complain at all.
* Is it reliable? well, I am now editing this post because I am about 500 hours down and it's been pretty reliable for sure, I cannot say I am unhappy with it.
* Upgrades needed? No, no bother. It prints fine as is and because I spend all day fixing machines, I am generally of the mind, "if it aint broke, don't fix it"
** Although - A cooling mod is recommended, easy to print and install but for PLA it's a must on this machine I say, flawless prints with a good active cooler.
* Print Quality? Once you get it sorted with the wobbling bed, yes it can produce prints as good or better than my flashforge of the same design
* It uses the exact same firmware as the flashforge dual (wooden version) so for those that own one (like me) all your slicing and software you were already using works on this identically - but it is a touch faster than a flashforge for some reason, just slightly - running them side by side the same print, the same Gcode, was finished in the CTC about 2 minutes before the Flashforge, so they have upped the acceleration somewhat, but still works fine with makerware and simplyfy3D.
* Prints Wood exceptionally well, no idea why it's better than the FF (possibly nozzle new versus nozzle old) but wow, it prints wood just outstandingly.

So the verdict.. Buy one? yeah for the money you really can't go wrong. In my country, it's about $500 for one, so really half a Flashforge with almost as good a build (they got the rod diameter right, no wobbles in that from the start)