I have to say the control mixed with... some of the decisions that went into level design is pretty horrible. You can't shoot while jetting, and there are enemies coming in from outside of the narrow screen just slightly higher than where you've ascended. You can't shoot them, and if you drop to avoid them, you may not get high enough to the next ledge before taking a hit anyways.
The cross shooter does not seem to do more damage, and it only shoots 2 at a time, and it's not enough to kill a gunner, then you have to wait for it to spin back, if it ever comes back straight. And why would there ever be an upgrade to revert to your initial gun??