My DS falls asleep on the boob as well. I used to feed in bed at night quite regularly but for some reason lately it has not been working for us -- I suddenly found it very uncomfortable and he wouldn't get as good a feed. So now I sit up to feed. There have been time though where I have gone back to that and he will settle for a bit sometimes. I also often do the 5am feed siting in bed and we both fall asleep that way for an extra hour.
It is more that in the day he won't leave my arms, which is both good and bad! I am hoping for the best with the swing. I prob won't know how effective it is until the week starts, as the weekends are always another story with DH around and all ...