50 and over 5k and beyond

Well apparently there are a bunch of us out there 50 and older, and we are either ready to finish the C25k program or have finished it. So, now what? Do you try to improve your time? Your distance? Both? Do you run races to stay motivated? Do you run outside, or on a treadmill? Is one better than the other? Are you dealing with any running-related injuries, and what are you doing about them