For the Sage, Aldaraan made a bit of a leap in difficulty. Before that it was a nice steady pace.
Quesh made another leap - the Attis Station (class storyline, lvl 37) was impossible as a Seer/Healer spec. I had to ask a lvl 45 Knight to help me. I was a little disappointed because I was under the impression the class storyline could be solo'ed. Instead, it was tedious after 4 days of trying every way possible. I respecing my skill tree twice and upgraded my gear, but still had to ask that lvl 45 Knight to come in and help me do my own class storyline!
The next planet, Belsavis, kind of leveled out a bit. But still had a few things to test the player (rightly so!)
Now I'm level 44. I'm on Voss, which seems to have taken another leap, and I'm not really enjoying it. It has a level range of 44 - 47, yet the class story begins with a Force-user boss at level 45 and all the side quests I find are 45 - 46, making it a grind to level up so I can continue my class story. PvP and Space combat only goes so far!
Even more annoying is, due to the difficulty and regular deaths, I'm spending majority of my money (between 3k and 9k each time!) on armor repair when I should be saving for Speeder Piloting Rank 2.
On top of all that, over the past couple of days, there have been some laggy terrains, disappearing and reappearing mods. It doesn't make things any easier!