Once upon a time, I disagreed with Keith on this point, but I have since come over to his side. Capture One has difficulty with very noisy images, although it handles low to moderate levels of noise quite handily. Even so, the checkerboard pattern may not be visible in ordinary size prints or on the web. In any event, I now use RPP for all images worthy of conversion to TIFFs. It has no noise reduction feature, so I perform that task as needed with Topaz Denoise in Photoshop. TDN is the best NR software that I have tried.
To summarize, with high ISO images, it may be best to use a raw convertor other than Capture One, but that decision depends on the ultimate output format and size.
Rob