I just bought the Electron Plus CTL503 a few days ago and I am quite happy with the functionality, after some initial trouble.
The max current (3A) and max voltage (100V) makes CTL503 more capable than other curve tracers that I have (Atlas DCA75 Pro & a selfmade Arduino based curve tracer).
Here are my thoughts after a few hours of playing around with the instrument.
Pros:
The max voltage and current: 100V and 3 A.
Both continuous and pulsed mode operation.
The CTL503 seems to handle NPN/PNP, NFET/PFET, Diode and SCR (I have only tested different NPN transistors so far).
All parameters that I can think of can be easily adjusted from the user interface.
The reult data seems to be very precise. There is also a calibration procedure that I havent tested yet.
All data from each run is saved in a text-file.
Cons:
The documentation is unfortunatly still pretty much non existing, see:
https://electron.plus/pages/manualsThere are still no reviews or information about the Electron Plus CTL503 on Internet.
The user interface is a bit buggy (the 64-bit version of the sofware was very unstable for me - the 32-bit version works better).
I miss the possibility to see exact data values with "mouse over" on the curves.