We enjoyed our 3-day stay at Cathy's place. The location is perfect - it is central, close to the public transportation, and you can walk pretty much to every major place of interest in Seattle. It's next to the Convention Center in the heart of Downtown; however, the neighborhood is very quiet. The apartment is not big, but for the two of us it was just perfect size. It is clean, nicely furnished, well-equipped and has all the amenities you'd need. Cathy is very professional, organized and prompt, and has a whole book of instructions and tips on sights, restaurants (organized by cuisine) and night life in Seattle, and we tried some of her suggestions and they were right on! And a nice touch was a basket of snacks she left for us on the kitchen counter.
Cathy was out of town when we stayed at her place, so she arranged for us to pick up and drop off keys at a convenience store a block away which has a key deposit box system called KeyCafe. I haven't tried that before, but it went smoothly. Cathy's instructions were precise and on point. Cathy also responded promptly to my messages and was very accommodating and flexible - we arrived earlier than her usual check-in time, but it was not a problem, we arrived to the apartment straight from the airport and it was ready for us.
Highly recommend!