I weigh 115 lbs, and I have a 32 pound all mountain full suspension Marin, and a 25 lb Titus Racer X.

The Marin is better on the terrain in the NE. It is heavier for sure, but it takes the hits much better. The lighter bike does not stick as well over the rocks.

I did a race in the Daks this past Sunday and rode the Titus. The terrain was better suited to the Marin.

I upgraded to the Titus this year to race on,and although it is easier to climb on, I carry more momentum on the Marin, so sometimes I wonder if it does not all equal out in the end.

Lighter may not be your solution due to your location.