I had such a wonderful stay at Sonder in South Loop. The check in process was seamless, the studio was beautiful, and the views were exactly what I expected. The wifi was very fast-- this helped as I was working remotely during my stay.
The area was super safe and convenient-- many restaurants and grocery stores nearby. Giordano's is right around the corner! The only thing that was a bit of a bummer was the inability to check in earlier than 4 (I had to check out of my hotel at 11am, so I was in a bind for awhile), and the inability to check out later than 11 (my flight out of O'hare was at 8pm, so it was a bit of an effort to kill time). The good news is that the luggage storage lockers aren't as bad as the other reviews make it seem. Sure, it's first come first serve, and there aren't very many lockers. Sure, two of the lockers had doors ripped out (which made me a bit uneasy at first). But if you plan ahead and pack up early, you should be able to fit all of your bags into a locker and secure one. My girlfriend and I locked up our bags at around 10am and headed to a couple of museums. We returned to the building (your code will work all day, even after your check out time) at around 4pm to start making moves towards the airport.
Overall, it was a wonderful stay. I'm glad I discovered Sonder, and I will most definitely be staying at the various Sonder locations all over the world!