NB: My ratings are based on the price ($35 for the one night I stayed).
I booked ahead by emailing the owner (Mr. Thatcher) directly and received a prompt reply and confirmation from him. I arrived late (after 9pm), cranky and exhausted after more than 24 hours' continuous travel. I was so happy to find Mr. Thatcher there and kindly willing to draw me a map to where I could walk out to get something to eat at that hour (I had not eaten during those 24 hours). By the way, the location is great, and, though I'm a woman travelling alone, I had no fear about walking out alone at night.
My room was on the ground floor, with double doors leading to the pool area. It was clean, and with a little fiddling, everything worked -- including the WiFi. The bed was indeed firm, as another reviewer pointed out, but that suited me just fine. Slept like a log. I didn't hear noise from the street, but the many birds in the trees by the pool do sing their hearts out in the morning. Not a bad sound to wake up to! The lock to my room was a little tricky for me, but a very nice lady (I'm afraid I didn't catch her name) repeatedly helped me with it with patience and good humour. The pool is in a courtyard, and has both lounge chairs and tables and chairs. It wasn't swimming weather, so I can't comment on the pool itself, but it was very pleasant to sit out there with my coffee and chat with Mr. Thatcher in the morning.
Breakfast is a do-it-yourself affair, at least on the day I was there. There was toast and coffee available, from what I could see, but I was only interested in hot water for my instant espresso. Two young women were happily cooking up a full breakfast for themselves while I had my coffee, and the kitchen, which is just off the lobby, seemed perfectly adequate for that. (I assume that they bought their own food supplies -- there are plenty of stores within walking distance.)
I had to wait until noon for my car to be delivered, and Mr. Thatcher was very nice about letting me leave my luggage in the lobby and loiter about the place after check-out time.
All in all, the Yucatan Vista Inn is a great value, in my opinion. It's clean, safe, and in a terrific area within walking distance of lots of things to see and do (and around the corner from the English Library, for those who know Merida). I will be staying there again, when arriving to or departing Mexico or after a concert in town, to avoid driving up to the beach at night (where I normally stay). I will also recommend it, without hesitation, to friends in Yucatan who are in the same situation. Just bear in mind that it's a casual place -- take a look at the rates and adjust your expectations accordingly. If you are high maintenance and like to be waited on, it's probably not for you. If you are a seasoned traveller, it will be a very pleasant surprise.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC