Each brand is very different and each user experience is different based on miles/usage. That being said my experience with the competition: 2001 Mercedes CLK 430(new) - loved it, super reliable, great V8, very comfy.(7 years owned), 2006 BMW M5(used, 12k miles) - bland interior, beast over 50mph, clunky and gas wh*re in lower gears, very comfy active seats, plenty small issues....usually electronic, bad menu/computer system. (owned 4 years), 2013 Audi S4(new) - Very fast, smooth gears, stunning interior, very good computer system and controls/steering, very uncomfortable hard seats. ( 1 year).
I figured I would write this considering I owned all three brands people will most likely compare to or come from. As for the X4, I just don't think it's worth comparing, then again I never liked the look of the Range Evoque and don't think it's worth comparing either, but people gush over it. I've driven many friends cars, 335's, X5's, S550's, Amg's etc. Don't worry about what others like, it's about what fits you best. That being said the above three brands all sell this many vehicles in the US, Audi, 158k, BMW 200K+, Merc 200k+. Porsche sold over 40k last year for the first time ever.
My experience owning the Macan S a month: The smoothest ride, stunning interior and amazingly comfortable seats, and I love the design. And it's kind of nice they won't make a ton(at least for now)...but given the reviews and owner feedback...I have no doubt this will be back ordered for some time to come.