Well, my brother is 6'11" and he is VERY comfortable in the front. Also, I have had to sit behind him and I still had enough room to be comfortable. The interior has many similarities to its bigger cousin the Audi A4. There are a lot of nice interior touches etc...
When at the auto-show last year, I felt that the Golf/Jetta had more rear-seat room than the Audi A4!! So yea, its plenty roomy insinde. And the rear seats fold TOTALLY flat. So you have a TON of space for your 21" monitor and computers.. or what have you. My brother fits his mountain bike back there with room to spare (although he seperates the front tire).
As for power? Well its all over the board. The tourqe comes on at @2400 rpm (can't say that about a Honda!) and is almost level to 6000. I haven't driven the car myself with more than another person in it. But to give you an idea of the power that the 1.8t has:
I was in Argentina with my parents on vacation, and we had a Passat 1.8t (the Passat is MUCH heavier than the Golf/Jetta). Same engine specs. With a FULLY loaded trunk, 4 adults, and a teenager (my sis) the car had power to spare! The tranny never felt overburdened, and I never even smoked the clutch once! This with all the mountains and hills around. Plenty of power, I can't imagine with the chip!
One thing that you MUST keep in mind about the 1.8t engine is that it is the SAME engine in the base TT. The base TT puts out 180bhp. The difference? Engine software... the ECU. So the 190hp chip that I showed you won't stress the engine too much more than the TT does. People have been running chips on their A4s and Passats for YEARS now. So its proven to be a strong engine, and reacts well to mods.
Anyway, let me know if you have any additional questions. There is a TON of cool stuff out there on those VWs.
-Skaven
(edit) and about the difference in 0-60 times in the magazines? There are lots of factors. It was actually a GTI 1.8t that pulled the 7.3 in C&D (It may have been European car though).. the engine is the same but the tires are better. Also the heat plays a MAJOR factor on the turbo performance. Add that to driver differences and it could be as big as a .5 sec difference. Also the jetta IS heavier than the Golf. Not by much, but it can make a difference. Also, I am not sure if the tranny ratios are the same on the G/J. <shrug>