i don't ski anything shorter than 180 unless it is park only. then it's like a 170.
but it is personal preference, height, weight, where you ski, etc.
for example: if you lived in jackson hole, a short, skinny ski would SUCK. you would want seth pistols, motherships, etc. as your primary ski in a 180 plus... at least.
but if you were at mt snow, your primary ski would probably be in the 170 - 175 range and be like a chronic, PE or a 1080.
of course then there is my brother who lives in oregon. he rocks the 200 straight boards (Salomon GS skis) for all applications. and he does just fine. his 'short skis' are a pair of a Kent Kreitler 192's... from like 97... and those are his 'new' skis.