When you first encounter enemies, you see their ship type and often have a choice to fight or not. I propose adding a bit more information here, so I can reliably determine (or guess) whether it'll be an easy or a hard fight.
However, as you progress through the sectors, enemies with the same ship types get stronger. They may have two or three shield boxes instead of one; they may have three or four bars' worth of weapons instead of one. I assume their dodge chance increases, as well. This means that knowing the ship type doesn't tell me how tough a fight they'll be. What I want to know is what their total reactor output is, or some other metric that indicates what "level" enemy this is.
Upgrading sensors may give me more specific information at this point (how many potential bars in each system), but this is pre-battle--I don't care about specifics, I just want to know the difference between a rebel fighter in sector 1 and a rebel fighter in sector 4.
I'd also like to get some mouseover information about enemy weapons. I can tell which weapons an enemy has just by looking, but it's a pain to try to remember which beam is which.