The ABT processor does not do anything with the component video output, so you lose the benefit of that processor. Blu-ray will be output as 1080i, but the Mediatek chip will be doing the processing instead of the ABT2010. You also lose the ability to scale DVD content (specifically DVD content that is CSS encrypted, which is most commercial releases), so you only get 480p at best from most DVD's even when you select 1080i output. The BDP-83 comes with an HDMI cable. Spend
$5 on an HDMI-to-DVI adapter and you're all set. Using component video output when you can use HDMI will be short-changing yourself.
The example of an HD cable box is not a good one to carry over to Blu-ray. For one thing, cable box makers are going for the cheapest quality possible, and the video processing I've seen from those boxes is dreadful. For another thing, their implementation of things like HDCP tends to be bad.