An SSD makes a very noticeable difference on PS3 and would highly recommend getting one but obviously they can be expensive so it's really a case of if you are annoyed enough by things loading slower. As for people saying it wont make a difference without trying it, it does. Maybe not completely performance-wise but the less strain on loading models etc means that it can focus on other areas and makes the frame rate more consistent. If you do decide to get one you wont be disappointed with the change.