I have been in the motor trade for 25 years and I have witnessed the development of headlamp bulbs throughout those years. I recently got my wife a newish BMW 320d without HID headlamps, thinking that the normal Halogen couldn't be that bad, well the first time my wife drove it at night, I needn't say anymore. I immediately considered an HID conversion, but as it was for the wife's car thought that keeping it legal would be the safer option. I looked for a legal upgrade and eventually after reading several reviews and forums decided on these, and I all I am going to say is 'why don't BMW fit them as standard', if they continue to make HID an optional extra.
It is scientifically impossible for replacement bulbs to actually significantly increase the length of beam from a headlamp as the reflector and lens control that, but they can increase the brightness/whiteness of light produced enabling the beam to be adjusted (within legal limits) to achieve the maximum visible beam pattern and these bulbs certainly do that.
I have just fitted some to my Mk 6 Fiesta and they have really improved those as well. (Please note that the fitment of bulb may not be the same for a BMW and a Fiesta, I meant that I had fitted this make of bulb to my Fiesta as well.)
If you have candles and want to stay legal, give these ago, they do not perform miracles, but you will not want to go back to standard Halogen bulbs.