Like Fez says, it *really* depends on the skier.
I remember when the Volkl Snow Ranger (sort of a semi-predecessor to today's G4) first came out. I demoed the 200cm length (which was much shorter than what I was used to skiing on at the time) and thought they were insanely easy for tree skiing. They felt so short it was kinda like cheating. Granted, the Snow Ranger and the G-4 are much different skis, but today a 200cm Snow Ranger would be looked on as an pretty burly ski.
My roundabout point is that shorter lengths make it easier. There's absolutely nothing wrong with that. But that definitely doesn't mean that if you have the skills you can't make a modern, long (by comparison) ski turn like the dickens in the trees.
Then, when you get *out* of the trees and onto a big, open, junked-up bowl, that long ski will wail like a fire truck.
Can you demo before you buy?