I loved the first Dead Space, the setting, the pacing, the interface.I can't praise Visceral games enough.
I started playing Dead Space 2 and so far, I am also enjoying it.
There are some differences though... the 1st game was slow and misterious, with the silent Issac trying to find the mystery behind the necromorphs.
The second game is more bloody and action-packed with lots of stuff popping into your face to scare you. I definitely need to be quicker and more precise with my fingers now.
A good comparision I guess it's with the 1st and 2nd Aliens movie. Both are good in their own way and both have nasty creatures ripping you, but I find the first more moody while the second throw a big alien queen on your face.
Oddly, when I find the 1st shop in the game they had tons of weapons and armos to sell for... free. Perhaps my Steam copy had some hidden DLC bonus content attached but so far I am avoiding it.. starting the game with good armor and weapons take a bit of the challenge.
tl;dr - Dead Space 2 is fun, a different kind of fun than the 1st one but still similar enough to praise whoever enjoyed the original.