Suspension is everything in roadracing. I'd take that over HP in many situations. Tires have improved speed and laptimes, along with the ever progressing technology of bikes (for example, in the 600 class where each model evolves every 1-2 years; pretty fast if you think about it).
Regardless, I'll take all 4 as part of a good package - even better if I don't have to try and rank them.
Cheers.