The main reason for the OSRAM was, among other things, in addition to the described and confirmed by users "warm white" light color, the appearance of the light source. Sounds weird - but irritate me in the off state of LED lamps always visible yellow "LED dies". This point has solved by the reflector cover very well Osram. These LED bulbs can see from the front regarded as conventional lamps from.
The light itself actually has a pleasant color. Mentioned in the package are 2700 K ("warm-white"). The emission of light, ie the light beam is directed than normal GU10 halogen bulbs. The specified replacement information (3.9 W replaces 35 Watt halogen) agrees roughly or is slightly exceeded, that is, the 3.9 watt version is slightly lighter than the 35 watt halogen version.
When researching the reports about me a (relatively frequent) premature failure of the lamps have a little irritated. Since I from the variants "LED STAR PAR16 35" (3.9 W) and "LED STAR PAR16 50" (5.5 W) have each bought 5 pieces and these are in use for today (11.29.2014) - I'll trying to report at regular intervals over the life.
The light source is, according to packaging "Made in Ukraine". Deviating from the specification in the Amazon Product (4.6 W), the lamp 3.9 W. I think I have read somewhere that the 3.9 W variant by specifying Made-in-Ukraine should be "preserved longer" ,
Conclusion
I have not regretted the move to LED under any circumstances. Priced there are certainly more favorable variants.
Light color, shape and appearance convinced - and the name OSRAM promises so far a leap of faith. In the life I'm curious.