Personally, I think the lex has better interior. BMW has better performance and style lines, by far. Durability? ehhh, that's about equal.
Side note: my car was rear ended and I'm in a rental. I've always like the Cadillac CTS. . . until I actually drove it. It reminds me of driving my old man's 67 cutlass (btw, if anybody knows where I can get body parts for the 67, please let me know - grazie). My 328 has more zip to it, too. Seems sluggish on the throttle. THe interior is more comfortable than my bimmer, though. Not too soft, not too hard - good seat contour, too. But it is very bulky feeling.