Is there advanced maneuver node functionality I'm missing, or are maneuver nodes just... bad? Catastrophically, game-breakingly bad?
It is near impossible to select the vector you want. I can only grab my desired vector if I zoom in reaaaaally close, which then makes it impossible to see if my orbit is intercepting my destination.
There is no ability to make micro-adjustments. You only adjust by pulling the vectors.
There is no read-out of how much you've pulled each vector, so if you accidently pull the wrong vector (which happens often!) you basically need to delete your node and start over.
It is very difficult to move your maneuver node along your orbit. Again, you need to zoom in reaaaaally close to select the ball in the center of node.
There's no way to change the phase of your maneuver, it seems? You can't "skip" orbits, e.g., to sync your maneuver with the Mun.
Please, please, please... focus on the maneuver nodes for your first update. They are so bad.
EDIT: Summarizing some other issues from this thread so we have a single list of what to improve:
You can't see your orbital line passing through other celestial bodies' sphere of influence, i.e., you can't see the path you'll be taking past your destination. You have to settle for a random encounter that likely has a highly eccentric orbit.
You can’t create or edit maneuver modes while paused.
There is no read-out of your expected result altitude (Ap/Pe, etc) from your maneuver.
It is difficult to time your maneuvers around Ap/Pe for circularization burns, because the maneuver nodes represent the start of a burn rather than the center of one.
Bugs galore. Sometimes the maneuver tracker doesn't start once you've started your burned. Switching to the map view resets your maneuver tracker mid-burn, sending you rocketing to an unplanned destination. Time warping doesn't work reliably; oftentimes you simply blow past the point on the orbit you were warping to.