hey dazza, you should practice both. they will both be used, but depending on what sequence of notes in the song you play will dictate which one will be used so proficinecy in both should be the goal. when i practice while going up the chromatic scale i used the side keys for the Bb and C notes and while coming down the chromatic it feels more natural to me to use the traditional c fingering and for the Bb i use the B and F keys. for me it is a smoother transition. your goal should be to be proficient in the various fingerings though because there will be certain times where one fingering will be preferred over another. good luck
Jake
