They are just different brands. I have a Lovelinks bracelet and I love it.
The Lovelinks is slightly cheaper (not sure how much by) than Pandora although the beads are still approx. $40-50 on average.
They also have different clasps than the pandora ones, these are the hook ones, where pandora are weird spinny things (thats my technical talk ).
I wear mine 24/7, I take it off for showering but leave it on to do the dishes and it hasn't hurt it at all.
I was told when I bought it that other brands of beads will fit on it but I have not tried so I cannot confirm that.
I do not know anything about thw Amora ones, sorry.

HTH.