I had an excellent time staying at Yuliet's place. She greeted me at the apartment and was ready to answer any questions I had. The apartment itself is very clean and well-appointed. If you're a light sleeper, you should be aware there's a decent amount of street noise, but it's about what you should expect from being right off a busy market area. The location is great--it's about a 10-minute walk from the main train station, and five minutes over to Via Maqueda. Street signs in Italy are hit and miss, but just follow the Ballaro market all the way up from the train station, and when there are no more stalls, you'll want the street that's at about 10 o'clock.
Even though internet is the last thing to think about when you have all of Palermo to see, I just have to point out that I was getting 457 Mbps over Wi-Fi, which is insane. I've never actually seen my laptop register that speed, so that was new! It's definitely a small thing, but rest assured, if you're traveling in Sicily and want to video chat with family back home, you won't have any issues here.
All in all, I highly recommend staying here, and I easily see myself doing so again the next time I come to Palermo.