Personal Preference - A larger size frame will be more stable, and will give you more room to move without upsetting the weight-balance of the bike. The larger size will put the front wheel further in front of you, which gives the feeling of security and conversely, it will require more significant body movements when you WANT to shift the weight-bias of the bike. Think hard about your riding style and how active/intuitive you want it to be vs stable and speedy. You'll need to work a bit harder to muscle the larger bike around.