I have finally purchased a box of the Luster paper and think it is great. I love the Canon Semi Gloss paper Canon Photo Paper Plus Semi-Gloss 13" x 19" (50 Sheets) (SG-201 13X19) and I see little difference between the two. Since I think Semi Gloss is five stars, I give this paper the same rating.I have attached an image to this review. (Reducing its resolution and making it a jpg makes it a little sucky but that's life on Amazon.) The image has a good range of colors and deep blacks with some details that are just visible. I used a handheld magnifier and one of those large desk-mounted magnifiers with built-in light ring to examine the two prints: one on Semi Gloss and the other on Luster, both 13x19 and made on my Pro9500 Mark II.My conclusions after examination are 1) whiteness, texture, and sheen of the two papers are virtually the same but see below, 2) colors are virtually the same, 3) details in highlights are virtually the same, 4) depth of black areas are virtually the same, and 5) discernible details in black areas are virtually the same. When I say "virtually the same" I mean identical to me but I admit that there may be some differences that have escaped me or might be more visible using a different printer. [By the way, the word "Canon" is printed on the back of Semi Gloss but not on Luster. This is fortunate since otherwise I would believe I had made the two prints on the same paper.]I'm not likely to buy much of this paper unless the price falls to match or better the Semi Gloss. Since I can't see any difference, I'll buy the less expensive. Further, I use 4x6 Semi Gloss for proofs and there is no small version of the Luster.This is below: With more careful examination, it seems that the Luster paper might be whiter but that difference is slight and only visible when 1) the two papers abut, 2) you move your head side to side, and 3) you exchange the positions of the papers a few times in case the light isn't perfectly even. As I said, the difference is very slight.Additional test: I increased the number of test subjects to three: 1) Semi Gloss paper using its own ICC profile, 2) Luster paper using the Semi Gloss profile, and 3) Luster paper using the Pro Glossy II profile. The third subject - number 3 - was motivated by the fact that Ilford recommends using Canon's Pro Glossy II profile with their Luster papers and Canon support recommended using the Pro Glossy II profile when I contacted them before ordering the Luster paper. The instructions included with the Luster paper said to use the Semi Gloss profile so I contacted Canon again and they confirmed using the Semi Gloss profile. Be all that as it may ...My conclusions after examination of the three test subjects are 1) whiteness, texture, and sheen of the two papers are virtually the same, 2) colors are virtually the same, 3) details in highlights are virtually the same, 4) depth of black areas are virtually the same, and 5) discernible details in black areas are virtually the same. When I say "virtually the same" I mean identical to me but I admit that there may be some differences that have escaped me or might be more visible using a different printer.So my recommendations are to buy whichever of Canon Luster or Semi Gloss that is least expensive at the time. They are both excellent papers and virtually identical. If you run tests like described above, please mention them in your reviews or attach as comments to this review. Please include printer information - I used a Pro9500 - since different printers might emphasize differences not apparent to me.