Sorry I didn't see you already nixed the CX idea when I posted. For some reason I missed it when I was posting. Anyway that is obviously understandable. Of the two you linked I'd personally go for the Marin, but as has been stated they are both fine. I have a '13 Trek Wahoo and both of your options have better components. I have ridden it very hard considering its an entry level mountain bike and it has served me well (although I would have spent more had I known what I know now). The front suspension and brakes aren't the best but they got the job done and the bike is fun. The good news for you is if you want to make it more commuter friendly you can lock out the suspension on the front fork with the flick of a switch and put some hybrid tires and it will effectively be a tougher hybrid. I got my girlfriend a '13 Trek Marin (yes I got her a better bike than me, but they had a color scheme she loved, and you know how that goes) and we turned it into a hybrid and she loves it. But we still switch the tires out and hit the trails here and there.

Best of luck! Don't forget to drop in and show us pics when you get it.