I may have overpaid a bit for a mint, garage kept Si, but I definitely feel it was worth it. Even with the mileage in the 150k range, the maintenance for me has been minimal. For my daily vehicle, the power is adequate for passing and accelerating out of sight from annoying drivers. The handling is excellent. Car is light and easily maneuverable. MPG (with 10% ethanol fuel) have been from 26 with "spirited driving" to > 30 when gas was $4.50/gal and I was trying to drive efficiently.
Positives have been the performance, the fuel economy, and the overall integrity. The 205 tires are perfect. Seats hold you in place but probably wouldn't fit overweight people. Backseat is pretty useless (this is a positive to me). Parts are easy to find.
I'm not sure why premium fuel is required. Oil changes are complicated because the filter is immediately above the exhaust and a bit difficult to reach.