It depends on the set. I know on many of the Samsungs, HDMI2 is also the input for DVI-PC, and many think that this input reduces lag because it disables some image processing (I think it's mostly the video game crowd that cares about this issue).
I know I have very little input lag using HDMI2 on my set, but haven't measured in against the other HDMI inputs. If I have time in the next day or two I'll pull out the cables and check it out for you.
On my Samsung tv there are certain features that require being plugged into HDMI 1 instead of HDMI 2....like using the TV as a PC Monitor...it won't recognize it in HDMI 2 but needs to be plugged into HDMI 1. The Manual states this..and your manual should tell you if there are any differences between the two.
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, TVs, projectors, screens, receivers, speakers, projects, DIY’s, product reviews, accessories, classifieds, and more!