Component verses HDMI

I would like to know if there is any difference, in the Video only, of using component inputs or HDMI to my Samsung 52″ LCD TV?

I am using a AV receiver for all my TV inputs, 2 SAT, DVD and then the AV receiver sends the Video to the TV and the audio to the suround speakers. There fore I am only using my TV as a monitor. Before I buy a HDMI cable I would like to know if the HDMI vidio is any better than the component. I have been told that component can not pass 1080I but HDMI can.