I have an Alltrack with the same AWD (GenV Haldex). This is my 3rd Haldex-equipped car (first VW with it). The system works great in the snow, without the fuel economy hit of a torsion system. I'm a fan of 3 pedals in the snow as well, which is a nice bonus on the Alltrack.
Ground clearance is 6.9 on the Alltrack vs 7.9 on the Tiguan. One thing about the Alltrack: you can get some crazy deals on them. I got mine last year at a 9K discount, and I've seem some pretty close deals on them now. Americans just hate station wagons. I'm guessing the Tiguan carries more of a premium.
I don't know about these expensive parts. I've never seen any 1K window actuators, and parts in general seem pretty cheap. The 2018's also have a 6/72 bumper-to-bumper warranty, which seems better than most cars out there. The Haldex system itself is quite robust. Change the Haldex fluid at least per the schedule, and change the front bevel gear fluid every 40K if you plan on keeping the car to 150K (unlike my Ford and my Volvo, VW includes a drain plug for both the front bevel gear and rear differential, so servicing is quite easy).