I stayed at Gabriel's apartment with my wife and dog for just over a month and would absolutely stay again. It's a very modern apartment with everything you need for long stays. Wifi was strong enough to support both of us on zoom calls at the same time with no problems. We did a good bit of cooking while there so I can confirm the kitchen works well. We only used one of the bedrooms but the mattress was comfortable, its very quiet because its in the back of the building, and the ensuite bathroom is convenient. I'm a light sleeper and never had any issues at all.
Gabriel was also an excellent host - happy to provide recommendations and always very quick to respond to any messages. There were only a couple times we needed help and both times he had a repairman or cleaning person there immediately. He's also your next door neighbor so is nearby in case of emergencies but also gives you plenty of space and privacy.
The neighborhood was great too. It's very close to all the great parts of Condesa but slightly removed on a quieter street so isn't very noisy. We never felt unsafe either though.
Overall, I completely recommend Gabriel's apartment and would happily book it again the next time were in CDMX.