personally.... the HFP lip which would be your definition of the "optional equip" is a shitty lip. yes It makes the car look far more aggressive, however, everyone single person with an SI gets that same lip. why not get a different lip and make yourself unique? i mean not everything has to be upgraded. from ex to si we get the (in my opinion) very nice looking stock rims, short exhaust, si only wing, k20, 6spd lsd tranny, si interior, red gauges, sport pedals and shift knob and with 08s you get the type r looking shift boot. so i mean from 3k-6k more youre getting all that in which the engine alone is 6k....
granted, from the looks of things they have added quite a bit more for the 09s... so every new year comes with more advancements. if you want the newest to come stock on the car, keep buying the newest years lol