If you cross a fix a minute early (as allowed) you'll more than likely get a vector or an earlier than usual speed reduction to 230/210kts etc (for sep or the sequence).
If you are doing 260 kts when you were asked for 250, you may get a vector or a further reduction to 230kts.
You can trust a Boeing to cross a fix at a stated time, you can NEVER EVER (EVER) trust an airbus to cross a fix at a stated time (or meet a level requirement). Airbuses get you stood down, Boeings are trustworthy.