Location, location, location. Sara's place is in a perfect spot, just a five minute walk from Brown Line, Lincoln Park, and dozens of restaurants, bars, and grocery.
The apartment is on a fairly quiet residential street (by big city standards), and its proximity to train lines made for easy moves to get further North, into the Loop, and out west to United Center or Pilsen.
We dealt with some wonky weather while there (from 20° to 60° with rain, sleet and snow flurries), but the place really did well during cold weather. We were a bit uncomfortable at nights when it wasn't so cold outside but the heat was going through the building, but that seemed like an uncommon occurrence, plus an A/C in the living room helped cut the heat.
The only real negative I have was the bed, but I'm a sensitive sleeper. It felt like a double-size memory foam mattress and was a somewhat tight fit for a couple (especially on the warmer nights), but especially for someone who's taller, it'll mean your feet hanging off the end. That's not a very rare traveling thing for taller people, but I really couldn't wait to get back to my bed, either.
Overall, a great find that made a busy trip easier, especially at the price point we booked. I'd consider staying again on another trip.