Crystalline and Epson Canvas Gloss are made by the same contractor. Right now the substrates and surface qualities seem identical. But if I use my Crystalline profile to make the same print on both canvases, the Epson canvas comes out MUCH punchier with considerably better d-max and much more brilliant highlights. So they are definitely not the same product.
Epson Gloss might contain OBA's, and if so I'm all for it. It can print certain important colors that are WAY outside aRGB, and considerably outside the ability of my 2690 monitor to display on the screen. The good and bad news combined is that hard proofing is pretty much required and I find myself making many more test strips and proof prints than before. Not all colors are outside aRGB of course, but the deep greens, red, and blues are real eye openers for those of use used to matte canvas. Plan to tone down those clear blue skies and green foliage.
Uncoated Crystalline is a little more resistant to scratches, but both canvases are hopelessly vulnerable to cleaning sprays and IMHO it is a serious mistake not to coat either one unless you display under glazing.
BC has mentioned that the surface of Crystalline is quite acidic and they are uncomfortable about quoting longevity. I note Epson is claiming their Gloss is "Acid Free." Does that mean something for longevity? Dunno but I can guess it does. There's a kind of pungent smell when I print of Crystalline, that is not there with Epson Gloss. I assume it has to do with the BC "no coating" technology.
Should mention that Epson has recently changed Epson Canvas Gloss very dramatically. Gone is the goofy screen door surface they used previously. If you buy any, be sure you get product numbers ending in 243, 244, and 245 for 24, 36, and 44 inch rolls respectively.
And both canvases come on super-stiff, 22mil, 400+GSM rolls which are complete PITAs in every way from edge head-bangs in the printer to pronounced curling afterwords. The last shipment of Epson Gloss seem to have softened the substrate a little, and the head-bangs are much easier to avoid. I'm hoping that's a trend. QC on both canvases is above average, which is a good thing considering the price.
Water based coating are strong solvents for both canvases. Maybe that's more pronounced with 8300 prints than with 9900 prints, not sure about that. Rolling is out of the question. You need a very thin, sprayed primer coat, then a couple more generous coats when the primer coat is dry to the touch. Not hard to do, but you really need to get your spray rates and technique under control for that primer step or you will melt your images. Both canvases can be easily coated with solvent sprays, including things like Deft wood spray from Lowes. If your setup permits solvent spraying, that's what you want.
In the last couple months have hacked through about 20 rolls each of Cystalline and Epson Canvas Gloss. On the walls both easily outshine the prints I formerly made on various matte canvases. Sales are way up. Folks are commenting how "dimensional" my prints look, which I never heard before. I'm now able to print some very sparkly, backlighted images that were complete flops on matte canvas. People like dramatic prints and that's a fact and that's why I'm sticking with gloss canvas for now.