Unloaded, rack and bar bag mount off is how I usually ride the bike. Lovely, stable and quick. Couldn't ask for more (Well apart from a non creaking brooks saddle...). On really steep hills in really low gears it easy to make to front wheel lift though.
Loaded, I've ridden it a few times with a bit of weight on the back, this was the first time with a bar bag as well. Panniers alone are alright but make the front very light, the barbag weighted the nose down and stabilised everything. I hit 43 mph coming down of Dartmoor and it was perfectly smooth and stable, changes of direction we fine and everything. At very slow speeds the bar bag was a lump that pulled the wheel round once you got going to just weighted the front back down.
In this photo, theres 3kg in the bar bag 2 full bottles of water, and around 7kg in the panniers (a good proportion of which was D-lock)
