It for sure doesn't turn as quick. It depends how you like to ride. The guys that like to do everything fast prefer the 155's. The 174 does it slower. IMO young and athletic 155. The older and slower you get, the easier the 174 is.
This is exactly why I just bought the 174 this week.
1st ride on it today confirms
I am coming off a 2017 163x3" too, and its surprising how differently the 174 handles than the 163 .... I'm a larger guy too, 6'3" and 230ish ... geared up ride weight I'm closer to 280, then add water bottles, survival gear and the stuff I put on the sled, so total I'm probably adding 300-lbs to the weight of the sled.
I don't know if I should have done this, but I bought a set of Zbroz springs for my 2017 163 last year and wound up going back to the stock suspension settings with the Polaris fat boy spring on the rear track shock.
I put the set of Zbroz springs on the 174 and haven't ridden it "stock" yet, but so far so good, it does seem very stiff in the rear though .... the nose doesn't come up nearly as easily on this sled, go figure.
Hope to get it in the deep snow soon