Issue ammunition is never shiny, especially rifle ammunition. All the XM855 I've ever seen has looked exactly like issue ammunition. As for accuracy, accuracy standards for M855 are "close" at best; it is not anything like MOA ammunition.
This "only fair" accuracy potential is because the SS109-type bullet used in M855 is a complex structure and it's hard to keep the jacket, the steel insert and the lead core as "precise" as a simple jacket with lead core bullet design. Bullets designed for accuracy, such as "open tip match" bullets, are made with a "front loaded" jacket, which makes the bullet's base much more consistent than FMJ-type (including SS109) bullets that are "back loaded."
All in all, XM855 should work about as well as issued, GI M855. It's the very definition of "bulk" ammunition, but it's made at a well run, modern and efficient ammunition plant, so it'll be pretty darn consistent, even if that consistency includes about 4 MOA (by some descriptions) minimum accuracy standards.