I like both of the cars but i dont know which one to get
Which one would you pick and why

Either one is a good vehicle. If you intend on owning it for more than 5 years, I would go with the Cadillac. Mercedes vehicles are wildly expensive to maintain and repair after the warranty is up. The Cadillac has a huge dealer network, and parts will be comparatively cheap.

That said, if you think you will own it for less than 5 years, it's really a toss up. Drive both and see which one you like best. You really can't go wrong with either.