Maybe things change when get to a much higher level( I am a Commander 2), but getting 1 xp per kill on ground combat is kinda annoying. It makes me avoid those missions because they are a pain in the ass with little reward. When you do any space combat the xp received is structured to the type and level of the other ship. Why is ground combat not like this? Why is it still worth 1 xp when you get to higher levels?
Ground combat used to be faster than space combat. So the 1s added up nice and quickly. Unfortunately, in open beta, they slowed it down, which both reduced the xp rate and maybe ground combat super easy.
As far as space combat xp goes, I'd say the rewards for escorts, cruisers, and the rest of the bigger ships are too high. Should be about 2/3rds of what it currently is.