Definitely not easier or harder as far as gameplay goes. If you carry over a character, you get some bonuses at the start that while worthwhile, definitely aren't game breaking. Plus the game is so non-linear, everything scales to your level.
The big difference is in the state of the game universe. If you don't have a savegame, then there is a "canon" version of the universe the game defaults to. It's not worse or anything, and it is a state that you quite possibly had at the end of the first game, anyway (though with hundreds of plot states carried over, it's unlikely to have it exactly the same).
So the game as a whole there's not that much of an effect. It's in all the little details that your ME1 savegame makes a big difference. And the details are the best part, anyway, right?