My car has a Superchips BluFin map and I've had no idling, kangarooing or flat spot issues. If the exhaust has been changed you'd be better going for a custom map.
Perfectly normal to run sluggish on a cold start, especially this time of year! Not as noticeable during the summer months, but it does take a little time to warm up especially if you want to push it hard! Last winter was my first of ownership and I had the paranoia something was wrong but learned to accept it's just copes poorly with cold starts / cold weather!