i've been one of the major proponents for being able to build quality bigs out of just ath, def, reb, and sb, even with 1s in spd, per, bh, and pass. i still think thats true, but i think for offensive bigs, speed is helpful in terms of getting to the line. i don't think it has a substantial impact on fg%. the press has changed a lot and im not really sure if you can still ignore it at center. it used to be true, but i am not as sure these days, it might be marginally helpful.