RK5000 AC power source. Has anyone bought one? Are they any good?

[InterestedTom]

Saw RK5000 on ebay and alibaba brand new shipped direct from china.

I'd like one in a way, don't have the money right now, but looking at the pictures would rather make my own in some ways (it's not very pretty!).

Features:

* Output capacity: 500VA
* Circuit mode:(IGBT)SPWM Pulse Width Modulation
* AC input: Single-phase AC 110V+/-10% 60Hz
* AC output:
Voltage: Low range 0-150V, High range 0-300V
Frequency: 45Hz-70Hz adjustable 50Hz/60Hz/400Hz(Optional)
Maximal current: L=120V 4.2A, H=240V 2.1A
Load Regulation: 1%
T.H.D: 1%
Frequency Regulation: 0.01%
Load voltage stabilizing rate: <=0.5%
Waveform: Sine wave
Waveform  distortion degree: <=2%(resistance load)
Efficiency: More than 85%
Response time: <=2ms
* Display and resolution:
Digit frequency 4 digits display, resolution 0.1Hz
Digit voltage 4 digits display, resolution 0.1V
Digit current 4 digits display, resolution 0.01A
Digit power 4 digits display, resolution 1W
Digit power factor 4 digits display, resolution 0.001
* Protection : overvoltage, over current, overload, over temperature and short-circuit, as well as automatic jump protection and alarm device
* Cooling: Forced fan cooling
* Working temperature: 0 degreeC - +45 degreeC, Relative 0-90%(non- condense)
* Dimensions(mm): 420(600)*420*190
* Weight(Kg): 30KG