Like many people I was put off by the trailer (a horrible representation of this show) but decided to give it a chance. I'm glad I did, though I'm still not quite sure what to think about it.
For what it is, it's a great first episode. The acting is phenomenal, and I love the actors' representations especially of Raven and Starfire/Koriand'r, whose confusion and amnesia was palpable. I can't wait to see how Raven's story develops. Robin (Dick Grayson, newly fallen out with Batman and on his own in Detroit) is a much different character from how he's been portrayed before. In the comics, Dick is quiet and serious, but with a cheerful and compassionate bent. There's none of that here, except in his fierce protectiveness of young Raven.
I think that's the main thing that gave me pause. Titans isn't pulling any punches. If you're expecting the warm, humorous "weekend club for teenage superheros" atmosphere from the comics, prepare to be shocked. This first episode is brutal and gory. It has a high body count (yes, most of those are killed by the Titans) and the violence doesn't show any sign of letting up.
Honestly, I'm not sure how I feel about that. I like dark and gritty, but I feel like this show may be going a touch overboard for the shock value. Regardless, I'm looking forward to the next episode and will be interested to see what comes.