I partially agree with the slow leveling complaint you have. It has taken me an age to get through the late 20s. I swear I could play for 8 straight hours (hypothetically) and only gain around one level. However, I really think it has to do with the quests you complete in a given area. Depending on your current level and the level requirements for the quest, you could potentially level really fast or somewhat slow. I think the reason for me leveling slow is that I got to Nar Shaddaa around level 24-25 when it says that the max level for the planet is 24. So, I'm probably a little high for the quest levels that are offered there and, in turn, gain less experience from the quests because of this :/ my fault for being a beast and powering up to 25 too soon lol