It's been a couple of years since I was out there last, but #15 looks a lot different -- seems like they might be cutting the tall grass down the hill to the left, and that they might have taken some trees out near the green. From the right tees, if you're long enough, driver is (or was) definitely a possibility b/c you could fly it to either the downslope or the fairway, and then get a kick near the green. Probably not prudent, but certainly fun to crest the hill and see where your drive has ended up.
Perhaps more than any other course in DC, one of the keys to playing well at Columbia is to miss below the hole, even if that means being off the green. The greens have a lot of slope to them (including near the edges), and they are usually pretty quick, so being short-sided is a disaster.
Fun course!