Both would be good choices, but I'd probably lean towards Ralph Lauren. As long as the ones you're looking at don't have the pony. I'm not a big fan of visible logos, but they do sell sweaters without them.
both about the same, both made in china. I have sweaters from both in the same size. Fit on the jcrew is a bit roomier and longer, so depends on what you like. quality is mid level for both. They aren't cucinelli, but they last well and look good.