Firstly, if you want to read some interesing analysis of Mini's, go here and read both the post and the comments (not mine, mine was terrible), then if you want to follow up, go here and read the comments.
Now here are some pictures of Titans I jammed together. Some are very old titans in the 6mm range. that means they are about the size of your thumb, or smaller. The others are modern Titans in the 28mm range. That makes them the size of your hand, or forearm maybe.