If blown out at ~150" like I'm doing with my 1080p projector, there's usually a fine but noticeable difference between 720 and 1080, things are a little more defined all over the place, like irises in eyeballs come out much less blurred, etc. But overall, in a movie as active as Star Wars, the difference is really not all that apparent.

And to the mac burning question, there was an answer mentioned just a few pages back; that being: http://forums.macrumors.com/showpost.php?p=9046125&postcount=18

and a follow up note of

"note: i'm not sure if it's necessary for success, but i first created CERTIFICATE and CERTIFICATE/BACKUP directories (empty) in the "Star Wars DE_2.1 AVCHD" directory. and then i did touch * in that directory to make sure BDMV and CERTIFICATE had the same date. then i follow the procedure at the above link.

i have a DL disc that plays on PS3 now!"