A longer toptube will net you a steeper headtube usually. A Steeper headtube angle / seat angle will quicken turn in and response to any turning input. A touring bike generally has a shorter toptube, and more relaxed angles for the seat/head tube. This makes the touring bike more stable as a more aggressive angle will make the bike feel more twitchy and a touring bike generally tries to feel a little more muted and stable.