I'm now on chapiter 11 or 12.
It's hard to elect the better one.
I think the first one was more difficult. Especially the scene with the necro that regenerated. That was nasty.
This one is more action.
It's like the alien movies.
The first one was a lot of suspense and subtile, the second was straight forward.
Not that it's a bad thing.
I like the action packed side of the second game, though it appears to be less difficult than the first one ( i cheated on the first one

).
I only died 2 times and several times were i wanted to see the death animation, because those are hillarioulsy good on dead space.
The zero gravity scenes are fun, with more liberties, though i would have loved to walk on all walls.
I'm 8 hours in now on normal, should have gone with zealot, especially with my zealot suit and a better force gun.
Got the refurbished slicergun because of the savegame on the first dead space.
Also tried a quick MP, lots of fun. Eager to play more...
Loving it (sry McDo)
Also played the Extraction trial on psn with move. Lot of fun.
And for dead space fans, watch the 2 movies.
The hardcore mode will be hard, only 2 saves for the whole game.