Welcome to our new beta design! Click here to go back to the old Newschoolers.
as said before the syntax and the antidogma are practically the same ski. the syntax is just lighter due to lack of material . if you need a more stable ski i would go with the antidogma.
if i were you i would go with the 172. im 6"1 and own the 178 ones (bought them when i was a bit smaller (like 5"8ish) and the size was and still is good for me.
hope this helps. you will never regret this decision. antidogmas are the best skis i ever rode (even if the topsheet chipping is enourmous, which i said before)
light, playful, good stiffness and good pop.
P.S if you kill urban or do a lot of rails (i mean really a lot) you might get edge problems. some amplid skis had issues with the edges and they ripped out. but amplid has a good warranty service so if this problem occurs (which it hopefully will not) you can contact them and the see what they can do.
fortunately i did not had this problem on mine, even if i do a lot of rails.
hope i helped you deciding. keep us updated or write a review if you are or are not content with the skis.