Replying to Stick with 176 or go to 171?

sup buddies, yeah you read it right the first time, im thinking of going from a 176 to a 171, Im pretty sure of the response im gonna get from this, but here goes...Last 2 seasons ive skied the AR6 in 176. im 6ft and 160 pounds. i need to get new ones as mine are super beat up but im thinkin of getting the 171. last season i got confident on 3s/5s/switch riding/rails/boxes. (i spent last season in Fernie, sick but no booter park) this season im heading to meribel and im going to session the park day in day out. ive always felt my skis have been too long to really progress my spinning/rails and  i reckon getting the 171 will help this? i used to rollerblade before i started skiing so im used to spinning/grinding. when i bought the skis i had them slightly set back from centre, but im thinking of getting my next pair centre mounted? i know you properly know your shit and im a bit of a rookie so any input you can give will be much appreciated.