I’ve used them for snowboarding to keep in touch with mates. They are as stated line of sight, they won’t go over a valley. The best I got out of them was about 5km, me at a gondola station and the wife in a bar in the town. I used to use them at home when my daughter was little. I live in an old 3 story house and I’d leave one in her room as we couldn’t here her if she shouted. She thought it was cool!
I’ve got some Doro ones from currys that are tiny, and some older Motorola’s.
I found them both to have good battery life and would last all day, as they took rechargeable battery’s you could always take extra, but for a day on the slopes they were fine.
I found the motos to have a better range but as there all limited in power 0.5w I think, there wasn’t much in it.