I used to use Gatorskins on my Synapse, in 23mm and 25mm sizes. They were fine. I still managed to pick up a goathead puncture once in awhile riding in Los Angeles. Eventually I moved to GP4000 in 23mm, 25mm, and later 28mm. Now I use GP5000 in 28mm on that bike.

On my Quick hybrid I use 32mm GP4Season. Maybe slightly less puncture resistant than Gatorskins, but a nicer ride and better traction.

I would rank them as such in terms of puncture protection:

Gatorskins > GP4Season > GP5000 > GP4000sII

In terms of ride and handling:

GP5000 > GP4000sII > GP4Season > Gatorskins

If you can find Gatorskins in a 35mm width, that's going to be a pretty good tire for your type of riding. 32mm will do, but 35mm will feel nicer on gravel and packed trails. Plus 35mm you can run a slightly lower pressure for a less jarring ride. If you were doing more road riding and less trail riding, 32mm would be a prefectly acceptable option.

My Quick hybrid has 32mm tires on it. Since I don't ride offroad much, this is ideal for me. If I did ride offroad more, I'd go 35mm or 38mm.