If you are fine with 12GB, there is always the Thinkpad T450S, which should have one of the best (if not the best) keyboards on the market, and is an ultrabook

If you are fine with 12GB, there is always the Thinkpad T450S, which should have one of the best (if not the best) keyboards on the market, and is an ultrabook with a very good battery life. I'm not sure whether you will be able to add more memory, though.