DCist, admittedly, was not in love with the first ArtWalk, the large installation of murals on the old convention center site at 10th St. between New York Ave. and H St., NW. The third edition of ArtWalk opened this afternoon, and while we still have many of the prior complaints about the space (Astroturf is unnecessary, and the backstops with tarps that make up the walkway are far from aesthetically pleasing), the artwork itself…