The +30 bulbs are described at the http://catalog.com/susq/hella/bulbs.htm
site described above. They are basically a standard Halogen bulb with a repositioned filament and a little Xenon gas for cooling and spectrum shifting that results in a more focused and visibly whiter beam than standard halogens. They are the same 50/60 watts, however, but focus "30% more light on the driving area". The +50 is the Phillips version of the same thing. As I understand it, and from what I have seen with the +30s on my car, most of the efect is in the low beam, with a little effect on the high beams.
site also has a page discussing the hyper blue PIAA type bulbs, as do many other sites that have tested them. The test results show less light output because many wave lengths outside the blue range are attenuated out (white light is a mixture of all colors, red, blue, violet, green, etc.). Objects look more blue white by filtering out the reds and oranges with a coating on the bulb, but less total light gets out. The effect is especially noticable in the rain, according to these reports. Again, it comes down to what you are looking for - a 'blue light special' or more light on the road.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E