This is the reply I got from Wendy at Torch regarding the differences:
Yes, there are reflow oven T200C+ and T200N+.
The difference between T200C and T200C+ is the temperature measurement function. T200C+ has this function, T200C has no that.
The difference between T200N and T200N+ is the temperature measurement function. T200N+ has this function, T200N has no that.
please see quotation:
T200C+ USD2338 FOB Beijing
T200N+ USD3076 FOB Beijing
So the + versions have closed loop control of the temperature, but I would really like to see something more tangible in terms of a performance comparison. The datasheet is pretty generic also:
T200C+ Unique Features
With all advantage of T200C
With better airproof function, the temperature is more uniformity.
With emitting smoke function.
With purifying and filtering exhaust gas function.
With single channel temperature measurement (multi channels is optical), T200C+ has been the first-class reflow oven.
I am also rather curious about the software. Does it work well? The datasheet screenshots make it seem like one of two things: ugly GUI with good functionality and it does what it says it does, or ugly GUI and it sucks overall.
Sorry for asking so many questions and thank you for answering them. I haven't been able to find this information anywhere on the internet. If I end up getting one I'm going to make a page specifically detailing every little thing about it as I'm sure someone else out there is wondering the same things.