So I got my PSP downgraded to 3.71 M-33 2 earlier today, after taking a good look at the games that person who downgraded for me they are all CSO's and really small. Because I got some games before it got downgraded (Gundam Seed & Lumines 2) which both are pretty big 800~ and 1.1gig. The ones on my memory stick were like 160mb N4SMW and biggest is like Killzone 554mb. So i looked up on the net and tried PSP ISO Compressor 1.4 and tried compressing Lumines to CSO and it had like a 100mb reduction or something. Well i did put it at like lv 9 compression, should i put it like at lower? How much difference is there then in size & quality of the game? If I turn an ISO in to CSO does this mean it will remove all the "movies"?