I haven't driven an 1.8T, but I actually think the 5-speed would be fine. PlaneCrazy said before the the shift points took some getting used to for him. I just took delivery of a 2016 GTI this weekend, and 6 actually seems to be more than necessary. After having a JSW spinning 2000rpm at 70mph, I felt like I was itching for a taller 6th gear in the GTI, which spins 2200rpm at 70mph. It'd built for sport, and has plenty of passing power in 6th, though. The GTI has a small shift indicator in the upper corner of the cluster display. It'll often be telling me to shift 2>5 or 3>6 or whatever. It's not obtrusive. It seems to be giving you hyper-miling shift points, putting it at 1400rpm or so for cruising in town at, say, 45mph.
The Golf gets wide swaths of fake brushed aluminum trim in S and SE configurations, but you get piano black in SEL configuration. (with automatic of course, and some other things like power sport comfort seats, which rock.)
The Mk4 GTI 1.8Ts had 180hp. The new base 1.8Ts have 170hp, and more torque, if I recall correctly, so it should feel at least as fast as the former GTIs. I'd have gone with a 1.8T Golf, but for the fact that you could only get a manual in the base, no-frills configuration. I wanted a few of the goodies, so that took me to a GTI. I've been very happy with it so far. The 1.8T would probably give me a few extra mpg's, but I've been getting 33-34mpg indicated on the display in extended highway driving, and I'm content with that. Running on regular unleaded, too. "Premium required to achieve peak horesepower" - per VW.