I wanted the wood to show through so I used the oil based semi transparent stain in either cedar or white pine (can't remember which). The elastomeric looked like it's only a solid color and the cool feel semi solid only came in darker colors. I was told the oil would last longer than the waterborne. But the oil isn't as easy to work with. The waterborne can be applied over damp wood and it dries faster so there's no fear that it's not going to be dry before night / dew sets it.
I can't recommend it because I've never used it but a company just up the road from me, Vermont natural coatings, has a product I would really like to try. One of these days I'm going to make some cedar Adirondack chairs for the wife. VNC has a waterproofer that looks tempting as long as you don't mind the wood turning gray.