I understand both the high-raters and low: these aren't programs of analysis and psychology, but character and scenery ... you know: TV. I'm not bothered by the deviations from the books as I haven't read them. The strengths of this show rest largely on the acting, because the plotting doesn't particularly matter. More importantly, series 2 reinstates the 90-minute format of the pilot; while this cures season 1's rapid resolves, it also means the occasional filler. Such is the life of TV program.
This particular episode is typical of the run: rife with chance encounters, ending with the villain carefully and succinctly explaining every detail of their nefarious plan. Realism isn't very important here, so the story dances along the ledge of believability, occasionally falling off. But mildly amusing escapism? Pretty good stuff.
There's just enough red herrings and character moments to keep the energy up. On the other hand, it's also like watching a freshly-born colt tripping over its own legs while trying to stand up: pandering to fans and visual tropes of the genre -- often as not doing it clumsily. But not so clumsily that we stop watching, so that's clearly a plus. And we can't complain about trying to add some fun to this world, can we?