For Epson 870 users:
I just printed one page with multiple photos taken from digital camera (Nikon 800). The Photos are mainly composed of people with background and one vase with flowers.
I print it on both Premium Photo Paper from Office Depot and on Epson Photo Paper.
On the surface, OD paper appears of higher quality. It's thicker and it's more like film than Epson's.
On human figures, OD paper has more problem with shadows. It tends to be blockier. For the background, OD paper has more problem with harder tones too. There are horizon stripes or blockiness on the green wall while it does not show up on Epson paper. The flowers look great on both. Anything bright looks nice on both. Skin colors look more natural and true to the original on Epson.
In general, OD paper has more problem with darker brown. The verdict: Epson Photo Paper looks better in general. Out of perfect score of 100, I would give Epson 85, OD 79. If your photos are mostly nature and not too many dark rocks, OD would 83. I would consider the printout of Epson close to photo you print from stores. I wouldn't think OD close ot photo because of the problems with shadows. I have never tried Epson Premium Photo Paper. It might be better.
I think my result only applies to Epson 870. If you don't use this printer, you should not take my result too seriously. $37.30 for 200 premium photo paper is still a great deal.
Note: my Photoshop is in 320dpi. All photos were shrinked and resampled from 72dpi to 320dpi.
Hope this helps someone.
cpliu