My impressions are as follows:
(+) Positive (o) neutral () negative
(+) Absolutely no flicker (tested on a switching power supply with DC voltage; wild flashing until falling voltage to 6 volts)
(+) No noise
(+) The light is scattered relatively very wide
(O) Due to the specified color rendering index of Ra 80 I have no neutral, light bulbs similar color reproduction expected. In fact, I was confirmed. The light has a slight green tint; Skin look pale and unnatural; dark red appear more orange. For color critical areas (make-up mirror, Food lighting etc.) the LED retrofit is not suitable, unless you put no special emphasis on a natural color reproduction.
(O) The board is "in the air", ie without lamps housing around it, in operation about 65 ° C warm. In a closed light it will inevitably lead to higher temperatures, which may shorten the life (especially the built-up small electrolytic capacitor).
() So far, I noticed no serious shortcomings.
Conclusion: Unfortunately, no suitable halogen replacement. For me it is incomprehensible that there are E14 and E27 retrofits in the same price range with much better color rendering (Ra> 90), in contrast, G4 retrofits of various brands still have a parlous state color rendering index, which was dated years ago.