I have Pro-Kit springs on stock shocks and it is pretty close to stock comfort/ride quality. It hugs the road better and rough roads are obviously more pronounced, but overall I would never go back to stock and am extremely happy with it. I can be driving down a rough road and still take a drink, which was NOT the case with my Eclipse that had Tien coilovers.
For the XI debate, there are two reason I got mine. $11k OTD with no problems (58k miles, Who can beat that??) and because I live at the top of a hill that you cannot make it up without AWD. Anything that isn't AWD sits at the bottom for a few days and I have even seen 4x4 trucks/cars down there on my way up in the past. It's very helpful especially with all the lake effect snow we get!