I have had both and I kept the 3010 because I found its color to be much more saturated, more vivid, and yet still more accurate. I think that is the biggest advantage for the 3010 even more than brightness in 3d.
What did I find in the 9500? I found Art was right. The auto iris bumped the black up and down in a distracting manner, so it was not such a great feature. The picture sure had pop and contrast, though. The color I just could never get to look right, at least not whenever I made direct comparison to the 3010's color. And the 9500's picture could not stand up to ambient light anywhere near what the 3010 could do. In 3d, the 9500 was competent, no ghosting, and real good contrast and pop, but the colors looked washed out in comparison to the 3010 in 3d. Sorry, 9500, but that is what I found with my eyes.
Falafala had the Optoma 33, the Acer 9500 and the Epson 3010 and reported he kept the 3010 for many of the same reasons I ended up keeping it, but that thread is sure worth the read.
Ack-bk had the 3010 and the 9500 and kept the 9500, so individual preference determines it.
The 3010 has 50 ms more lag than the 9500. That did not bother me once I tried them both on some ps3 3d games, but for those who want a responsive game control, like for online shooters or racing games, the lag on the 3010 would be unacceptable.
However, for all around use in a living room, the 3010 is a beauty. It's combination of good contrast, great color, vividness and brightness, plus 3d redefines home entertainment. However again, you just can't go wrong with either of these or even with some others as well. We are in a golden age of home theater.