Yes it is a 5 series competetor but they don't make the 166 any more, the 169 replacement not due for a good while yet. The same thing happened previously when 164 ended production, there was a gap until 166 appeared!
I would say that the majority of 166 V6's have the sportronic box, the manual is fairly rare. It was when I was looking, I almost settled for a sportronic. Seems to be a big car thing!
I think you will find that all 5 series models are offerred in manual or auto - Customer choice is probably to the auto option.
http://www.parkers.co.uk/cars/used-p...l=buy&plate=73