I'd say this one's a strong sequel, although the final boss isn't as much of a nail-biter compared to X.... I didn't even feel the need to grab the last energy tank.

I liked how if you want to get Zero's parts; even if you knew every boss weakness ahead of time it can mix up the route you take through the initial stages which is juxtaposed pretty well over X's original loop of backtracking to earlier stages to grab things once you have more beam types and armour upgrades.