I have some longer cheap cables and I have serious issues with the DRM failing. I get a picture, and it tells me I'm not allowed to play on this device or
... .A few of the wrong missed bits and you get epic fail. Technically speaking to meet the spec the cable should be tested to fall within specifications for signal delays and losses, but I have a gut feeling the quality control on my cheap cables is not the greatest. So while the short cables you can probably get away with crap, anything on the longer end might be worth getting something other than the cheapest.