Visually it was pretty good but lost it big time when they didn't stay true to the original.
I would argue they did stay true.
They just broke the eggs and made a new omelet out of it, but it still has the same ingredients.
Considering they had to reinvent true icons that are known and loved beyond the trekkies and sci-fi community, they had a tough road to go. To stay 'true' to the original, they would have had to cast impersonators and then inject stories into the established timeline. Can you imagine the debates and arguments over 'when this could have happened' and 'Yeoman Brand wasn't in THAT season' etc. They have room for errors, as it were now.
I also find it interesting that we are not going to watch in anticipation as Kirk and Spock bond. There is an added pressure here. They HAVE to bond. They've been told that they are meant to be the best of friends. For me, it will be more interesting watching them try to figure out how that could even be possible considering the differences in personalities.
The back story on the characters was great. Something we never had before. Chekov is the teenage wunderkind. Sulu obviously uptight and on edge yearning for guidance and acceptance. Bones- the whole divorce thing, being older, wiser- you can't help but like the guy. Scottie - not just a genius but you get to see where his arrogance comes from.
My only issues were with Spock, arguably the most recognized icon of all of them and the sci-fi world. No one will ever be able to fill Leonard Nimoy shoes. He defined what it is to be Vulcan. In all the years I have watched Trek, I have not been able to keep from comparing every Vulcan interpretation to his and only two have come close - Suzie Plakson on STNG and, though I hate to admit it, Kirstie Alley in Wrath of Khan. For me, this new guy has got to pull it together. He definitely needs to be more restrained. However, I think they have left him an out by having him witness his mothers demise. And the whole BS storyline with Uhura has got to go away. In her case, I feel like the writers copped out on even trying to give her a back story.
What I will be looking for is deeper exploration into who these characters are, especially the lesser characters. They have the opportunity to do what the series didn't really try to do until the end and then in the movies. What I will really be keeping an eye on is Kirk maturing (as Captain, he can't be hitting on the crew), Spock's struggle with who he is, what he thinks he is, and what he thinks he should become, and the inner relationships of the the rest of the supporting characters and what happens that unites them so strongly. (The crew is 800 to 1000, so what is it that draws this particular group together. It's a 'military' operation, they would be working in rotating shifts 24/7 with different officers, etc. So what binds this group as a whole and to one another?)