I took a childbirth ed class from a chiropractor, and she did say not to put baby in an upright carrier until she was able to sit on her own (i.e. 6 months or so) so that damage won't be done to the hips. Something like a Moby or else a newborn insert that keeps their legs in but still allows baby to be upright when they want to is nice until they get to this stage.
I have been using my carrier (mainly my Moby) more and more with my 3 month old and looking forward to having it when I fly solo with her over the holidays - it seems so much easier than having to cart around a huge stroller. I don't find it much use for housework yet as I can only wear her in front, but I think it will definitely be a lifesaver when she gets older. It's also wonderful for walking outside in the winter (body heat helps a lot to keep her warm!) and for if she gets fussy in the stroller at the mall or something.
I also have a friend who can pretty much only get her little one to chill in her Bjorn (and she probably tried 3 different carriers before that - it just happened to be the one that worked best for her). It really does depend on the baby, and sometimes they'll love a carrier this week that they hated last week, so do try it again if it doesn't seem to work well the first time. Good luck! :)