Old thread revived.
So, I've had these bulbs since the bike had 79600 km (49440 miles) and I've been really satisfied with the extra light they provide. I paid around 25USD for the pair. That was in May 2014.
Yesterday, after 26 000 km (16 150 miles) the right one finally gave up. I'll be changing it the next couple of days, and I'll be fitting the same thing. There's always the obvious trade off in light output vs life span in this type of bulbs; my experience has been that I had already changed the OEM ones after 50 000 km (31 000 miles), so they last twice, and cost half. I am perfectly happy with spending 12.50 USD every 2 years (hell! every year would also be absolutely alright!) in order to get the extra safety.
I'd like to point out that the burnt bulb is the one on the right (as I mentioned) which is the side that was broken when I had a small accident in April '15, where the headlight assembly got broken on that side. I got a new assembly but the mechanic saved the two bulbs. So that might be a factor why the right one burnt first. I'm curious to know when the left one will give up.