The Nightbreakers are not the same as the SilverStar Ultras.
The Night Breaker range consists of H1, H3, H4, H7, and H11.
They are reasonably comparable to the Philips Xtreme Power in terms of raw light output; the differences between the two are not necessarily systematic (neither range is consistently better than the other), and these differences are almost unmeasurably small, certainly imperceptible in terms of actual headlamp performance, with the exception of the high beam mode of the H4 bulb, in which the Philips is definitely better. The Osram Night Breaker has relatively large areas of blue glass which do nothing for your seeing performance -- so-called "whiter" light does not help you see better -- but there is a colorless window completely surrounding the filament, so the tinted light is primarily confined to the extremities of the beam. Both of these bulbs have the best available output from a standard-wattage bulb, and an accordingly short lifespan (no free lunch). The law of diminishing returns applies here: there is a significant improvement in beam performance when going from a long-life to a standard bulb, an equally significant improvement when going from standard to +30, a smaller improvement when going from +30 to +50, and a smaller improvement still when going from +50 to +80/+90.
As for the various "plus" claims (+30, +50, +80, +90, etc.) keep in mind how they're devised: The plus-numbers cannot be attained simply through greater intensity from the bulb, because of intensity and wattage restrictions contained in bulb regulations prevailing worldwide. The "Plus" bulbs do produce near the maximum allowable flux but that's obviously not the whole story. These bulbs have higher filament luminance and give better beam focus because the filament coil itself is smaller. Headlamp optics are calculated based on a point source. The smaller the filament, the more closely it approximates a point source, and therefore the better the focus of the resultant beam pattern. The better the focus of the beam pattern, the higher the beam peak intensity (that is, the brighter the "hot spot"). Depending on the particular bulb and the specific headlamp optic in use, the gain in hot spot intensity can indeed be up to 50% (80%, 90%, whatever) at some specific but not uniform or predictable point in the beam. In practice, that means once Osram or Philips or whoever have designed their newest bulb, they throw the nearest convenient intern in a room with a bunch of headlamps and have him photometer them until the one that gives the single greatest increase (at any point in the beam!) is found, then they give the intern a food pellet as a reward. Tungsram called their 2nd-generation upgrade H4 "+60" either because they were lying or because they found a headlamp for a 1983 Tatra or something that had 60% more light in one particular spot. That doesn't mean the Tungsram "+60" H4 was better than the "+50" bulbs from Philips, Osram, and Narva -- it wasn't! So, those "+30" and "+50" and "+80" type numbers are not necessarily a trick or a scam, it just doesn't mean what most people assume it means.
We do have the full Nightbreaker line in stock at our secure Candlepower webstore:
Here is some more detailed info:
For reference, here's manufacturer data, from internal engineering databases, for output and lifespan at 13.2v for standard-wattage H1 bulbs. The numbers here are a composite of values applicable to the products of the big three makers (Osram-Sylvania, Philips-Narva, Tungsram-GE). Each manufacturer's product in each category is slightly different but not significantly so. I picked H1-type bulbs for this comparison, and while the absolute numbers differ with different bulb types, the relative comparison patterns hold good for whatever bulb type you consider. Lifespan is given as Tc, the hour figure at which 63.2 percent of the bulbs have failed.
H1 (regular normal):
1550 lumens, 650 hours
Long Life (or "HalogenPlus+")
1460 lumens, 1200 hours
Plus-30 High Efficacy (Osram Super, Sylvania Xtravision, Narva Rangepower, Candlepower Bright Light, Tungsram High Output, Philips Premium):
1700 lumens, 350 hours
Plus-50 Ultra High Efficacy (Philips VisionPlus, Osram Silverstar, Narva Rangepower+50, Tungsram Megalicht, but not Sylvania Silverstar):
1795 lumens, 350 hours
Plus-80/90 Mega High Efficacy (Philips Xtreme Power, Osram Night Breaker):
1780 lumens, 250-300 hours
Blue coated 'extra white' (Osram CoolBlue, Narva Rangepower Blue, Philips BlueVision or CrystalVision, Tungsram Super Blue or EuroBlue, Sylvania Silverstar or Silverstar Ultra, which is just a rebrand of the Silverstar product, also PIAA, Hoen, Nokya, Polarg, etc):
1380 lumens, 250 hours
Now, looking over these results, which one would you rather buy and drive with? The answer depends on how well you want to see versus how often to change the bulb. If you want the best possible seeing, you pick the Plus-50 or Plus-90. If you don't care as long as it works and you don't want to hassle with it, you pick the long life.