To be honest, I only took the risk of taking my own camera apart, because I didn't fancy sending it back to China - only to face the risk of import charges on a replacement that could potentially have the same issues.
I haven't yet done anywhere near enough testing, but comparing the ColorVu to the Varifocal version of the Dahua that I have - I will make the following provisional comments...
The Hikvision is about 25% cheaper than the Dahua, looks physically less imposing than the Dahua, and has low-light (in colour only) performance that equals (perhaps even beats) my old 2MP 1/1.8 Darkfigher.
Compared to the old 3MP Hikvision cameras with 1/3" sensors (such as the DS-2CD2032-i), the difference is a bit like switching from a decent compact digital cameras to a DSLR. When it comes to poor lighting, the ColorVu is certainly in a different league.
Sticking with the digital camera analogy, though... Using the Dahua is a bit like the first time you remove that cheap kit lens that came with your DSLR and stick a really good piece of glass on it. Even at 1:1 (100% image zoom), the picture is crisper and even more detailed than the Hikvision ColorVu in daylight and dusk conditions. Only in very low light does the ColorVu start to take the edge (colour accuracy is also a strong point)
The Hikvision ColorVu is clearly designed specifically for people who want the best possible colour images in low light conditions - for an affordable price. And for under 150 euros I don't know of any other camera that comes close.
On the other hand, the Dahua (about 50 euros more expensive) might not quite match the ColorVu in terms of ultra low light colour, but when switched to night mode with IR disabled - it does benefit from that typical improvement in detail and noise that everyone probably notices on their own cameras when they first switch over.
I haven't done a side-by-side comparison to confirm my theory yet, but my suspicion is that the Dahua might just beat the Hikvision in terms of being able to resolve the most detail in low light (with equal shutter speed and despite the aperture) - at the expense being able to tell what colour something is.
I will keep you all posted.
Craig.