I've ridden a ton of boards ranging from regular widths to wide widths in the 147-165 range.
I currently have an Evo in a 157. Although I like it and it does very well for my purposes, I chose to go with a 154 next time around. This is because the more I rode other freestyle boards in the 154-156 neighborhood, the more I wished I went a size shorter.
I can do everything on a 156 that I can with a 158. It's just that I prefer the smaller size when it comes to all-mountain freestyle. In the end, the effort to compensate is minimal when sizing down. It's more effort to compensate when sizing up. I strongly dislike riding anything bigger than 158 unless all I am doing is bombing runs all day.
But at my weight, 158 is the normal range for me. 155 is the normal range for your weight. By going with the 158, you're actually sizing up.
And by every means, the blunted tips really do reduce the actual length of the board without reducing the effective edge. My 157 proto rides like a bigger board but handles like a normal 157ish board.
Edit: If I were 165lbs looking for a one quiver size, the 155 would be my choice. Especially if I already own a 158 size board.