The Sirion GTvi is a bargain pocket rocket!!! In stock mine did 0-100km/hr in 9.1 seconds and it only cost $17,500 AUS. That's enough to beat a hell of a lot of under 2L cars.
Have modified with a 2 inch cat back system with Hi-Tech Bazooka muffler, and a JR Air Filter (pod style). After installing exhaust system: 0 - 100 dropped to 9.0 seconds. After air filter mod, 0 - 100 dropped to 8.6 seconds.
Handling isn't great. Heavy understeer when cornering hard. The understeer seems to come suddenly though. You enter a corner too quick and you "feel" that the car will be forgiving, but the next second, you will see yourself inches from the next light pole!!! A set of 195/50's on 15 inch rims and a rear swaybar should improve this. Mine came with crappy 165/65R14's with no rear swaybar.
Comfort is reasonable for a cheap small car. Typical japanese car feel (not a bad thing)
Adjustable seat and steering height would be nice.
Seats are quite supportive but maybe a bit high.
Gauges and switches are all fairly ergonomically placed.
Sound system is decent (comes with a Kenwood CD deck).
Very fuel efficient even with modifications. Max of about 8L/100km with lead foot driving!!!
Insurance is quite cheap at the moment - but when they figure out that the car is actually a giant beating pocket rocket like the Swift GTi, then they will surely jack up the price.