The likes and dislikes for this are certainly going to be based on personal tastes and opinions, heh. I think any fan of the original series and cast (of which I am) will appreciate this and other efforts (such as Star Trek New Voyages) to continue the look, feel and messages of the original show.
Star Trek can roughly be divided into two eras - Roddenberry, and post-Roddenberry. As a fan of the original, the first movies and TNG, the Roddenberry era is what works best for me. I think (and bear in mind it's just my opinion) that Roddenberry was a good sort of compass as to how the series should be and where it should go. Except for Start Trek V... that was just... you know what? We'll just omit that one. :P Anyway, post-Roddenberry, the series began to do some weird things to me, it just started on a real downward spiral. The TNG movies seemed to get progressively worse, Deep Space Nine was kind of dark and boring, Voyager was a real roller coaster ride of hits and missed and Enterprise was just awful. The new Abrams reboot takes it so far off the beaten path that it doesn't even seem like Star Trek anymore.... to me, anyway.
So, in a Roddenberry-era sense, this new series is very good - certainly true to that feel, and true to the original cast behaviour and mannerisms. Cast-wise, I think it's fantastic that Dohann's son is playing Scotty, and was surprised to Mythbuster's Grant playing Sulu (though I think he's trying way too hard to be George Takai.... ohhhhh my). It's amazing that they got Michael Forest back to play Apollo, and they did a fantastic job on the various age-based states of health. Heck, even Maria Sirtis signed on to do the computer voice, cool.
One thing I would question though, as has been mentioned, was the choice to use the 5:4 (or 4:3, whatever it is) aspect ratio - that seems a rather bad idea given the year. I hope future episodes will switch up to at least a 16:10 format or wider. I think as the show progresses (if it progresses), the actors will also get a bit more comfortable in their roles and it will seem less strained.
Ultimately, for those of us who like the Roddenberry era, this is a nice tip of the hat and a good alternative to the modern movies. :)