This is Zombie's thread, not mine.
Based on the Mits hc3800 and hc4000 thread, I have seen almost no color wheel failures. I've been in those threads for years, there have been a couple out of hundreds, if not thousands of users. Sure some don't post if it fails, but in general it's rare. I can find dust blob issues posted almost a hundred times in some threads.
I stand by the fact that color wheel failures are fairly uncommon on modern projectors that early on (but anything can happen), they may be more common on a Benq, I do not know. I have put well over 5000 hours spread across multiple DLP's including the one my friend owned (I owned the hd1000u, hc3800, hc4000, and now the Pro8200), never had a color wheel problem. I have however had contrast panel burn-outs on LCD projectors, as well as dust blobs. Current DLP has 1200 hours, no issues either. Another guy I helped out had 7,000 hours on his projector without a color wheel failure.