I love the lake, the views of Pike's Peak and Garden of the Gods in the distance. On a hot summer day it has a cool breeze and shady spots with a level surface all the way around. In past it must have been beautiful but seems neglected now with dead trees and bare dirt spots where used to be grass. Parking lots are riddled with potholes, so beware.
The wildlife is uplifting – a great blue heron, Canada geese, ducks, fish, and very friendly squirrels. The loop is actually 1.25 miles, so 4x around is a 5 mile workout.
Though parts of the park are cared for, there is an overall feeling of neglect, and an atmosphere of people hanging out with nowhere to go. Homeless people occasionally pass the night. And even in the early morning, some of the people using the park made me feel uncomfortable as a woman walking alone.
I'd recommend you go with a buddy.
I've done this one a few times, with and without dogs. It's a nice concrete trail around the lake. You'll often see people fishing, and ducks in the lake (as well as seagulls). I've heard bad things about this part of town, and this park, but I've not had any bad experiences. Memorial Park is nice, and has some sculptures throughout the park. It's home to the COS balloonfest every year. The lake is on one end of the park....with a nice view of Pikes Peak and the surrounding range as you walk around the lake.