Hi Jan,
S3 landing is EASY, believe me. However, forget everything you know about S3. S3 is not an indication of what SSM2007 really is.
Improved guidance is not a guarantee for an improved manual landing proficiency, especially with a more accurate flight and Shuttle handling model (think crosswinds, etc).
Imagine you need to land a B-747 manually. You have tons of guidance equipment but that will only tell you how you should fly towards the touchdown point, not HOW to handle the aircraft.
Same here. If you've landed heavies + sail-planes in Microsoft FS then you'll feel very comfortable at the controls. If not, then "practice makes perfect" and as we stated in the FAQs, each mission has an entry point for approach + landing trainng so you can do that without affecting the mission, and practice landing at KSC and EAFB as many times as you need.
/Admin