Mathieu is an amazing host and we really enjoyed staying at Casa Belga. A maid and a pool cleaner come to clean every week, making the place wonderfully spotless. There is also a nice projector for watching movies and the pool is great to cool off from the heat.
If you want to go downtown, simply take the 52 North bus for 8 pesos, or grab an Uber. Even though it's not right in centro, it was very easy for us to get around by bus. The neighbourhood is super safe, upscale, and full of wonderful, friendly people. To do your laundry, there's a laundry mat across the street that does laundry for 9 pesos/kg on Tuesdays. Cheap and convenient. And there's a Super Aki grocery store nearby that had everything we needed.
We also visited Mathieu's bar, which is the only place serving Belgian beer in all of Merida. So good! And he also introduced us to his friends who took us on a super fun trip to see a concert.
Had a blast and will visit you again the next time we're in Merida!