My personal take on your three points, from my own, personal perspective about my wife's car.
- If you want gadgets, and a newer chassis, the X3 will indeed be a better fit. It is most clearly an SUV and feels heavier and more ponderous than the X1 though, still fun, and still sportier than the competition, but not the car like feel of the X1. The X1 has been available in the ROW for years now, and it is an "e" chassis car, an E84, not the newer "f" chassis line, like the F25 X3 or the F30 3 series.
- This one could be touchy, as it's personal opinion. I like the M Sport on lighter colors, and the Sport or X Line on darker colors. We have a midnight blue with terra X Line and it works perfectly. I wouldn't prefer the M Sport body or painted lowers for this car, but understand why folks like it too.
- Again, personal opinion, but for my preference, being a "manual only" sort of guy, I dislike the feel of the newer ZF 8s transmissions. They're always shifting and it's really easy to catch it out of the power band, they have an immediate need to get to the highest gear possible. I feel more inclined to monkey with the paddles with the many cars I've driven with the 8s, and that sort of defeats my personal goal of what an automatic should be about. We had the 6s in my wife's previous 135i and it's a great transmission and works great with the N54 and N55. Honestly, one of the things that made it easy for us to choose the E84 X1 over the F30 335i or an F31 328i was the 6s in place of the 8s and the fact that there's no Auto Start Stop to deal with too.
To me, the X1 is about the driving experience, not the gadgets. If you'd like a newer, plusher design, an X3 28i might be worth driving. If you want a sportier, more spartan car, the X1 probably fits the bill. A good friend of mine has an E91 3er wagon that's a great car, but in the US, they were all 328i models, same as the new F31 wagon. The E84 is one of the few ways to get a hatchback with the N55 in the US and it works great for us.