As mentioned earlier, Osram's LED does an especially nice job with directionality, putting light out evenly in all directions. Bulbs in the 40W category are often used for accent lamps and side lighting, and if you end up reading a book under one late at night, you'll want to be sure it's omnidirectional, like Osram's.
It also helps that Osram's bulb offers plenty of brightness. Ideally, a 40W replacement will ring in at 450 lumens or above, and in Osram's case, we measured it at 496 -- higher (albeit just slightly) than other 40W replacement we tested. That's especially impressive when you remember that Osram's LED also tied for the lowest power draw of any of the 40W replacements in our lab.
Less impressive was Osram's color-rendering score, which gives you an idea of how accurately it illuminates different colors and tones. By today's standards, an LED should hit a score of 80 (at the very least). However, Osram's 40W replacement clocks in at 78, the same disappointing score as its 60W counterpart. More and more, we're seeing bulbs scoring up closer to the nineties -- including inexpensive bulbs like Ikea's Ledare LED. With competitors like that, Osram would likely be wise to get that score up a few points for the next generation.
Something else that an increasing number of consumers are factoring into their bulb-buying decision is dimmability, which is why the majority of today's LEDs promise you'll be able to dial the light up and down. That's a good thing -- but some bulbs do it better than others.
Osram's bulb is dimmable, and worked on every dimmer switch we tested it on, but it wasn't a perfect performer. We caught it flickering a bit at low settings, and also noticed that it wouldn't dim down quite as low as its big brother, Osram's 60W replacement. I give Osram's dimmability a passing grade here, but only just barely (though it certainly did a better job than).
If I were buying one of these bulbs for its dimmer compatibility, I'd rather have the Cree 40W Replacement LED, which offers similarly solid across-the-board performance along with less flicker on dimmer switches. Dimmability sticklers might also see the $12 Philips 40W Equivalent LED as a justifiable splurge, as it showed the strongest overall dimming performance.
Grabbing a 40W replacement or two is often a great, relatively inexpensive way to get started with LEDs. To this end, I think Osram was wise to keep things simple with this bulb. From the inconspicuous design to the solid specs, there's a lot here for an incandescent hold-out to appreciate.
For an LED with a longer warranty than the 5 years Osram offers, consider the Cree 40W replacement, which doubles your coverage and only costs $2 more per bulb. If strong dimming performance is your top concern, then the Philips 40W Equivalent LED is probably your best bet. But as a value-priced LED that's both simple and solid, I think most will be perfectly happy with what Osram's offering.