It all depends on you actually and the main audience you're trying to get to.
Honestly blood could make for a more appealing deal depending on how extensive we're talking here. I myself like a little blood but don't like ripping heads off with the spine following, ripping hearts or guts out, or showing internal organs.
It's nice to make a good median between the two for example you could show blood but as a little "hit" indication. Like if I had my character hit an enemy, the enemy would glow red for a split second and have an animation showing a little blood splatter just to indicate you're dealing damage.
How ever, some people more than most, depending on your game's atmosphere, could be a huge hit with them if you have a game that should include some gore. The most famous example is Mortal Combat:
http://youtu.be/PosEXd39r5g?t=7m16s
The tittle with gore sold more than the tittle without just because mortal combat is a gore filled game and people love that! Honestly if you're looking for a balance ask yourself these questions:
Does your game atmosphere call for gore or blood?
How much gore or blood is acceptable for you?
Who is your target audience? Young, teen, or mature?
In my case if I wanted to make a sci fi horror (which I'm doing now), I'd go along the lines of this: Yes the game atmosphere calls for blood, a basic or decent amount of blood or gore is acceptable but not excessive. My target audience will be for late teens - mature.
Deducting from those questions I would add gore as a way to portray the horror in the game but not too much so to cause the game to be too gore filled (Blood stained items, blood from enemies, damaged [but not mutilated] bodies, and blood along the walls and what not).