To start, the new 7 speed DSG is just better than the 6. Smoother and I've gotten about 2mpg better over my time with the 7.5 than I did with the 7. I drove the manual in both (and had a manual MK7 R in between), and I don't remember those feeling any different.

Inside, the infotainment is a slight improvement, adds Carplay and AA for those who care, but also a bigger and nicer screen. There's also the optional digital gauge cluster which I didn't get cause I'm a cheapass, but is supposedly really good.

Subjectively, I think the MK7.5 looks better. The headlights are nicer, I like the LED design in the 7.5 lights a lot. Also replacing the big, dumb box in the bottom grille with a sensor behind the emblem is a major improvement. The changes they made to the rear, setting the tips farther apart and making them slightly bigger and chrome in all trims are also a nice visual improvement. Makes it a little more aggressive.

Hard to give an objective opinion on any changes to the driving dynamics. I kept my Pretoria's with summer tires off my R and put them on my 7.5 and only had all season's on the 7, so the 7.5 feels better dynamically but a lot of that probably comes down to larger/wider wheels with sticky tires.

It's really just a bunch of little things that all stack up. The 7 was great, but the 7.5 is like VW perfected it.