After watching 2 full seasons:
1. Pace: is very slow; appears they are stretching the storyline as far as they can to maximize number of episodes sacrificing quality and tightness of the overall story arc. Found myself fast forwarding often to get to something meaningful or interesting. Gotta have an action scene, acrobatic sword fight every now and then too. This isn't The Matrix or a Marvel movie, people. It's Tolkienesque and should refect as much in EVERY element.
2. Characters: some are very good, well defined, well acted and mostly true to Tolkien's vision (Galadriel, Elrond, Gil-Galad, Sauron). However, too many new characters that contribute to a strung out story (see #1) and that can make things, while not confusing, a bit laborious to watch (little people/Hobbit precursors, elves/others that were never in any Tolkien works, etc).
2A: Numenor/Numenoreans: see #s 1 and 2. Could have really streamlined this piece of the story.
3. Dialects: OK, so the elves are "British," the hobbit-things "Irish," the Dwarves "Scottish." Very annoying and silly way to differentiate them. Also hues to tropes and stereotypes and takes away from this being about MIDDLE EARTH (not the UK!).
4. CGI: is pretty good. Some scenes are too much copy cats of LOTR movies, e.g., large battle scenes. Gotta. have some big, huge troll appear somewhere and some crazy, big snake like thing as well; oh, and something that may or may not be Shelob I guess.
5. Dialogue: is at times a bit trite and at others interesting. At times a bit cryptic (I won't spoil it but "The Stranger" - what a dumb name for this character btw - meets a very significant someone along the way in season 2 and the conversations are so vague and obtuse that it does nothing to advance the plot).
6. Cinematography: some nice aspects to give one a sense of being in Middle Earth; Khazad-Dum for example is evocative as is Celebrion. Numenor is a bit too CGI rendered for my taste. At times too freakin' dark though and can't really see what's going on in those wights or caves or wherever these characters end up to fight some evil ghouls of some type.
7. Score: Adheres to a lot of what was developed by Howard Shore for LOTR movies and tries to expand upon it. At times, way too ponderous and overwhelming like EVERY scene is the end of the world or something. Too forward in the final production to add emphasis or excitement or drama or fear that should be more fully delivered by the characters and action themselves.
Could have been a lot better with a tighter cast of characters, storyline, and focus on key elements of the SA as defined by Tolkien.