You have to take this as its own entity and if you do, it's a very enjoyable movie. I like some of the things the little things they did. Controls based on the airliner model, danger warnings on the screen like on a HUD, landing gear on shuttles, shuttles designed to parachute drops, shuttles turned sideways to maximize space (without atmosphere they're not going to need as much room to maneuver), the impulse engines shutting down right before going to hypsp.. I mean warp, and Starfleet having both working and service uniforms. Though the admirals looked a bit out of place and like the had been called back from a Cinco de Mayo part.
However, they did get somethings wrong too. The galaxy destroying supernova (trying to save the Romulan system because of the shared heritage would do), the seemingly complete lack of understanding of Military procedure (No clear chain of command, promoting everyone to their late TOS ranks right away, the use of "resign" instead of relieve), no announcement that the Enterprise was being sent out with mostly a cadet crew or a clear explanation as to why it built so much later, etc. All of those could have been easily corrected. I would have also preferred Pike make the announcement instead of Chekov.
As for the Characters, I think they were all in character or at least a version with understandable differences. Sulu and Uhura were fresh cadets and not the seasoned officers of 2265 TOS. Spock may have been relatively "space green" as well as the Enterprise has not existed yet for him to serve on. McCoy was dead on has story had not changed. Scotty was pretty understandable for basically being marooned. Lastly, Kirk had lived a very different life, but much was the same.
In closing, honestly there would have been a few things I would have done differently. I would have launched the Enterprise as planned in 2245 with the academy stint being between five years missions and the Enterprise undergoing major yardwork at Riverside. The Spock-Uhura romance I could have done without (not very logical). I also would have not destroyed Vulcan as its just too radical change. That being said, Nero's carnage does leave a lot of issues for the sequel. Nero won in the aspect that the Federation and the Klingons are severely weakened leaving a door open for Romulans of this time period. I think this may be the first piece of a three-part story.