Sienna's style really does a 180 when she's with Jude. She seems to really vamp it up and dress in a sexier way with Jude, like she looks here recently with Matthew Williamson. Whereas without him she tends to veer on the super girly side and doesn't come across as overtly sexy. I tend to like her style better with Jude than without him.
As for her sanity or emotional health, well that's a whole other can of worms. I just hope it works out for them this time.