I owned the 2015 GLI Auto, It did not disappoint me at all in terms of speed. I achieved 160 km/h with 4 people (including me) on motorway with ac on. (got fine though in the end!!!) i was desperate to take a picture of the speedometer but my mother was reluctant!!! lolz
Fuel Economy wise, it gave me 12.5-14.5 in the city! it all depends on driving style, i periodically checked the tire pressure (Eurostar tires), got the air-filter cleaned once a month. 3s maintained. light foot driving, turned of ac when not required. and guess what!!! oil change was mineral toyota 20w-50 (which i later regretted on why i agreed with the 3s person to go for heavy oil)
When we got the car out of showroom, the alignment was out and the car wobbled but we got that fix after 500km (45 days period to cover 1000km but I couldn't achieve that as i had other cars to fulfill the tasks, they called and said to bring the car for inspection)
sadly we had to sell it for personal reasons but till now i still miss my black beauty!
in the end i would still say that it all depends on how you drive as well as maintenance done on time!