My daughter turned 2 a month ago, and we just moved her to her big girl bed this last weekend. She was sleeping fine in her crib, but we just felt it was time. When she was sleeping in her crib, half the time, she would be sideways, all crunched up with a foot sticking out of the crib, etc...
She has been so excited to be in her big girl bed. We got a twin bed and put bed rails on it. I was going to read her a 3rd story last night, but she wanted to climb up in her bed and go to sleep instead. She has an older brother, and I didn't realize that she really wanted to be in a regular bed like him. She has been all smiles from ear to ear everytime the subject of her bed is brought up.
She's really a pretty naughty girl, but we haven't had too many issues with her getting out of bed. I just make sure that she knows how to get back into bed, and if I hear a lot of playing in her room 10-15 minutes after I put her down for a nap, I go in, be stern and tuck her back in. That's really been the end of it. I've been really surprised!!
*BTW, it isn't really too early. I moved my son at 17 months to a double bed with bed rails because we needed the crib for his baby sister, and he never had any sleep issues.