Any Disadvantage Using DVI-HDMI Adapters?

I don't think so - quality is not compromised - after all it is all digital. Provided the source is outputting data that the TV can decode. I use DVI-D (digital) to HDMI from my Mac to my HD TV - this way I can select tracks to play from the listening position by using a wireless keyboard. Note that when (if) they start protecting video against piracy then some devices will not accept digital HD signals except through HDMI...

( I had to hack the Mac standard operating system by programming the Video card to output 720p, as this was not a native resolution on Mac OS but it all works seamlessly now)

As I don't know your setup I can only relate my experience with adaptors and such. In my case dvi and component are the same. Mt tv,a 3year old Mits /without hdmi--but has dvi. ----I would guess because my tv is only 1080i is the reason. (?) Just to complicate things I guess it might also be the quality of the component cables I use. For a 1080p set I would say hdmi should be the way to go.

Thanks for all responses. My 720p projector only has DVI, no HDMI. Guess I just have to try out and see if DVI-HDMI would yield better picture quality compared to the component cables that I'm currently using.

On another note, is there a difference between a cheap HDMI/DVI cable(probably <$10) and a branded cable like the Verastarr costing more than $200?

I use monosource.com for my cables, they are priced well and they have hdmi switchboxes, dvi-hdmi cables, etc. You may want to confirm that your dvi port is hdcp compliant (can you connect a cable box to it?) to receive hd content on it.

Ryder,
Non whatsoever, assuming the quality of the wire is the same.

HDMI carries audio and video
DVI carries video only. It has been the pro standard until HDMI came along.