Have a 2004 A4. Engine is very flexible, performs when asked and returns reasonable economy, so happy with that. Quality...a little disappointed with the finish on one or two things...doesn't seem to be holding up as well as I'd like. There's just that ride and handling connundrum..
More nimble than it has a right to be, so long as you remain committed, otherwise it can get a little unsettled and will sit up in protest.
Fairing does a good job of keeping the elements off, but it is big, so it's not too surprising that it gets pushed around by the wind a bit, especially in the turbulence around lorries.
Does it weave? I can't honestly say it weaves, but it doesn't really feel quite right either. It always feels like it's 'squirming'. Oddly enough its much more stable two up, which compounds my thoughts about it squirming. I tend to run the rear spring at the 'statndard' setting, but with the damping backed off a little further than standard as this seems to give the rear wheel a better chance of staying in contact with the road....