Yeah mang...if it doesn't look good, you have no commitment to jump.
I'm getting better at spotting and the first one that I did on my own last weekend, it looked dicey, just a bit farther than I wanted to jump from. But I went anyway and managed to make it back without a problem. There were some other student solos behind me and all the tandems.
Once I get down, I find out that after I jumped that they did a 180 and another jump run. I was talking to my instructor on the ground and she made it very clear that if you don't feel it's a good spot, you tell the pilot to turn around, or you let the people in front of you go first and then you turn it around.
I guess the point is that if it doesn't feel right for you, then don't do it.