Sorry for the long thread title, but I just wanted to follow forum rules about subject headings... anyway...
Why on earth did R* not give 360 owners the option to install to the HD? All the issues associated with the technical quality of the 360 version compared to the PS3 version, is due to reading off the DVD drive. Also, reading off the DVD drive will cause heat (never a good thing in a 360), noise, and reduce the life of the drive. I assume lots of seeks, and that's not a good thing to do to a DVD drive.
Here is the killer, they will have DLC for the 360, so the code to read data off a hard drive already exists. It's not like it would have been a huge development effort to treat the main game like DLC, and just stream it from the HD.
If I was a 360 only owner, I would find out if this is due to a MS policy (or technical limitation), or find out if this was the discretion of R*, and send whomever is responsible a petition.