We tiled the entire ground floor of our new build and put some Devi electric heating mats underneath the tiles. Come on for an hour in the mornings in winter to take the bite out of the coldness. We have a 19 month old that has never had a problem learning to walk on them - never once banged head, knees, etc. As another poster says, they are only toddlers for a minute, and do you want to be looking at a rubber floor when the kids are teenagers?
Personally we find the tiles to be great - make the rooms look bigger and lighter, plus flooding, puke, and various other baby bodily secretions are not a problem...