I disagree. The only enemies in 3 that require you to aim independently from locking (such as the first boss) force you to do this even if Lock On Free Aim is turned off.
It really does come down to personal preference, like I said before, and I personally think that the freedom it gives you when it's turned on in all games is preferable.
I've actually never played 3 with lock on free aim off, so it's interesting that it forces it off when necessary. That said, what I should have said is that 3 was clearly designed to accommodate the lock on free aim, while 1 and 2 were not, and it's noticeable. Even early Prime bosses such as the
war wasp mini boss
Is the "normal" mode too easy?
I enjoyed the opening level, but it really was a breeze. The boss went down in seconds after I realized it's weak spot and I didn't go down more than 85% despite taking a few hits. I had assumed this was just because this was a first level and the difficulty would level out.
However, at the same time, I don't have the time for a super tough game these days.
I want something challenging but reasonably doable. Should I stick to 'normal' or bump it up to the originals normal?
Normal in Prime is pretty well balanced and none of the bosses are overly complex. Most of the challenge in the game comes from figuring out where to go rather than combat anyway. Some of the bosses can be pretty challenging in Echoes, though, but I think it's a better game for it.