Summary: I've been wanting the I5 processor for some time. Didn't really feel the need for an I7. There is not a huge difference that I can see between it and the Q9550, but just by updating to the LGA 1155 socket and DDR3 memory, it's made a big difference in productivity and speed. Outstanding product.
Summary: It's not like you can really say anything bad about Intel. I've built machine after machine with AMD and Intel chips, and overall, I keep leaning towards Intel for their lower temperature, longer lasting CPU's. I paired this chip with an OCZ Vertex 4 250GB SSD, and this machine SCREAMS.
Summary: This processor is insanely fast for the price. I wish it had hyperthreading like the i7 does, but I don't often need it so I can't complain too much. Works well with my mid-level ASUS motherboard. Totally stable.