I stayed at La Cartuja for a week, while on a business trip. La Cartuja started to feel like home. I talked to all the people that worked there, who would ask me how my day went.
My room was very large with 2 beds and a fake fireplace. The beds were well-made and comfy to sleep on. My room was right next to the lobby, which made it a little loud (buzzers and people in the hallway). The room could also be a little cold at night with the tile floors, so bring some socks and a sweater!
The big bummer was that the Internet didn't work that well in my room. That meant that I often used my phone to hotspot or call abroad.
Breakfast was decent with eggs (made fried/scrambled), toast, fruit, and some yogurt and granola. There was always fresh juice and coffee/tea.
The location was pretty good. The hotel's right next to the Ecuadorian national museum. It's a 15-20 minute walk from the heart of La Floresta and about 10-12 minutes from La Mariscal. The only thing is that it's not super safe to walk at night, so in the evening I primarily got around by taxi.
Overall, a great place to stay when looking for something a little low-key and homey.