We bought the decals for my 7 year old sons bedroom. The walls had just been painted so were in good condition. The stickers we easy to peel and have a strong adhesive, although you can remove them easily if you've 'misplaced' them. The tree is floor to ceiling in height and there are plenty of extra leaves to place around the branches. It looks fantastic.
I followed the tip of a previous user and cut smaller pieces off the leaf decals to make application easier. I also didn't use the lettering or birdcage - all these pieces are seperate so are suitable for a boys room.