Just bought this to replace my W1070 lamp for the second time, I'm at about 12k hours on the machine. First lamp blew up at 6500 hours and clogged a fan, had to spend hours disassembling the PJ to fix it. If you're over 5k hours, you NEED a new bulb.
OEM lamp assemblies are the most hassle free, best performing option. The W1070 OEM replacement price is typically about $230 shipped, which is what I paid from B&H in late 2015.
$159.20 with FREE shipping. From BenQ USA via ebay, one of the few sources of a genuine replacement lamp assembly.
There seems to be other lamps available for other models.