I have some of the ROX, the pellets are tiny. the 0.8 stands for the size of the extrusion (0.8 mm I think). Imagine little pcs of mechanical pencil lead. The std lignite carbon they sell is good stuff too, the "large" size is about the consistency of kitty litter. I believe their std carbon has a higher molasses number relative to the Iodine #. In English, this means their cheaper carbon is better at decoloring and removing the larg(ish) organic molecules than their premium ROX product. Rox, has a higher iodine #, which means it has more small pores relative to large pores. Thus ROX is more effective at adsorbing simpler, smaller compounds. For aquarium applications, we're generally more interested in carbons with high molasses numbers and decoloring efficiency than iodine numbers. Everything they sell is steam activated and washed with phosphate free acids, and you really can't go wrong. However, I'd probably give the edge to their standard product. It's as good (or better) than anything else generally available that I've seen.
As far as GFO, their regular granular GFO is the industry standard, It appears to be the same stuff in phosban/etc. There are only one or two mfg's in the world that make this stuff, AFAIK bulk reef is the only vendor to bring the high capacity to the aquarium market. Regular GFO has a fairly long lifespan in the average tank, I don't know what add'l value the high capacity would bring.
Hope this helps.
