I would say that came up to means roughly the same as approached (that is, move into close proximity with):
She came up to the window and asked to buy four tickets.
whereas came to can be used to mean arrive at:
I remember the day the veterinarian came to our farm and brought the bad news.
Obviously, there is some overlap between the two, because when you move close to something, you are also arriving there. Because of that, I would say that you could always use came to, but you wouldn't necessarily always be able to always use came up to without a possible slight shift in meaning. For example, in my second sentence, if I were to say:
I remember the day the veterinarian came up to our farm and brought the bad news.
that might imply something different. It could imply the doctor walked up along the road and stood at the fence (as opposed to in the original sentence, where it's easier for me to imagine the veterinarian in the kitchen). Another possible interpretation after adding the word up is that the veterinarian came from further away – in other words: I remember when the veterinarian came up [from the city] to bring us the bad news.
However, if I said:
She came to the window and asked to buy four tickets.
that pretty much says the same as the original, because we approach a ticket counter in the same way we arrive at a ticket counter.
As a footnote, these usages don't include more idiomatic uses of came to, such as:
I heard the trivia question on television, but it wasn't until I was driving in my car an hour later that the answer came to me.
The boxer was unconscious on the mat for a few seconds before he came to.
Literally, this phrase means "unusual," since "like few others" is logically the same as "unlike most others." That is, the person or thing you are talking about is not similar in some way to the other people or things that are in the same category.
In addition to that literal meaning, the phrase like few others is almost always used in a positive sense. Not only is this person or thing unlike most others, they are also better in some way than most others. So your example:
...what a job they’ve done, like few others have been able to do.
can be read to mean the same as:
...they have done a better job than most other people could do.
Best Answer
"The first morning bus" leaves the possibility that there are other types of bus, some of which could be earlier.
I've heard of "night buses", but I've never heard of "morning buses".
So that is possible but less likely. You probably mean that there are no buses leaving earlier than 5:30am. And for that the first sentence is better. But there is no need for "in the morning" and "am":