The 5oz size is perfect for trying out. I felt like 2.5oz was too small to really be able to stretch it and see what the texture is really like. I'm glad I did because I got some really nice ones. The banana floam slime smells just like banana candy - definitely tempting to bite into it, but thankfully the label says NOT to do that. I was surprised by how different the butter and memory dough slimes were - they looked so similar but felt really different. I think I liked the butter one better just because I like a more "weighty" slime. If that's something important to you, just FYI.