I actually use both fleece and wool depending on the condition. If I am going to be on a hunt where I know it is going to be wet and rainy, I will usually opt for the fleece. Fleece simply dries faster than wool. I wore fleece on my Kodiak bear hunt this spring.

If I expect it to be drier and windier (say like Colorado or above the Artic Circle), I like the wool better because it cuts the wind better than fleece.

As for gortex, I use it, but it will NOT keep you 100% dry if you are out say ten days in constant rain (which I have been before) tent camping with no chance to dry it out. Eventually the pores will get saturated and some moisture will wick through. You won't get wet, but you will get damp. The flip side is pvc type rain gear like the Helly Hanson stuff the commerical fisherman wear. It will keep you dry no matter what, but you will sweat, so you end up damp. The bottom line is if it is raining constantly for days on end, and you are in a tent, you are going to get damp no matter what. Best bet is to pray for a sunny day and take the time to dry everything out.