[ImperialCrown]

The later, the better I say. These PM/MK vehicles were greatly improved in 2009-on, although 2007-2008 aren't a lost cause.
On earlier ones, drive it for suspension/steering noises. Struts, ball joints, tie rod ends and control arm bushings could be prematurely worn.
The plastic interior trim quality and appearance was also significantly improved in 2009-on.
Although both came in FWD or 4WD/AWD configurations, the 4WD Patriot had the slightly more capable FreedomDrive II and had a Trail-Rated badge, whereas the Compass was a basic AWD.
If off-roading prowess is an important consideration for you. Both were great in the snow.

 

[MoparNorm]

Exactly what ImperialCrown said. You'll find the higher quality materials and better interiors in the newer versions.

 

[link3721]

I'll try not to repeat what'sbeen said. I've had an 09 for over 4 years now, over 63k miles. It's been a great ride both on and off road. Only regret was not getting the manual. Not that I don't like the cvt (I've come to appreciate it over the years) but the fun factor of a manual is what I wish I had. Also, leaky sunroofs have plagued both Patriots and Compasses, so keep an eye out four that.

Afterthought, it seems like I've gotten better fuel economy over the years, so making sure to get the latest software updates definitely helps the cvt.