The problem is you have no idea how the advanced class is going to turn out. I got level 18 on my Agent, as Sniper, and then I realized I don't really like sniper all that much. I don't want to have to get all the way back to level 18 as operative. Sniper doesn't do the damage output I expected, and has pathetic range compared to what it should have(I think sniper should have 200 yard range, not the same as smuggler)