Not that they need to battle it out, or are necessarily independent of eachother, but the differences between these two BDSM outcomes I think become garbled in many people's minds. It is probably apparent intuitively, but to realize their difference I think is an epiphany, and can help one communicate better with one's dominant.
I define each type like this:
Pleasure: Sexual excitement or arousal resulting from pain
Comfort: Any positive, protective feeling one receives from taking punishment
As I said, I think the two can be experienced together, but the motivations are different.
It is interesting to think about what one's goals are when engaging in BDSM. You may have one goal in mind and get there repeatedly. You may have thought you had one goal, and then someone takes you on a completely different path, or elicits feelings or memories that you weren't aware existed.
This is an incomplete post, but I find this topic so fascinating that I had to write about it right away. Any thoughts or ideas are welcome.