I've owned my '05 GP GXP for 5 years now and although I love it, I am getting the itch to try something different. One problem I've run into is there are very few cars out there that I like better! I'm thinking of getting one of the below and wanted to see if anyone had any past experience, horror stories, recommendations, opinions, etc on these especially as compared to my Grand Prix. Thank you!

07-08 Cadillac STS-V
08+ Cadillac STS 4.6
07-09 Infinity M45 Sport
08+ Infinity G37 S
09+ Jaguar XF
09+ Hyundai Genesis 4.6
08-09 Pontiac G8 GT
07+ Lexus IS350
11+ Kia Optima SX
07-08 Acura TL Type S

These are generally in order of my preference. As you can guess, I'm really leaning towards a luxury RWD V8 sedan. I've read some horror stories about the Jag XF, but it's soooo perdy!! Any other opinions?