I stayed there in April as a Hyatt Globalist and had a positive stay. Benefits were recognized automatically with no fuss. It's a boutique hotel with more character than the standard Hyatt Regency (for example), but otherwise it felt just like any other Hyatt in the US. Self parking is free and in an adjacent parking garage; valet parking is also free for hotel guests with valets stationed on Main Street in front of the hotel.

The hotel comprises an older building (the original El Capitan Hotel) and a newer buildout that were (re)developed over the past few years. The two parts of the building feel slightly different (e.g., the carpeting in the old hotel is more classic while the new hotel had more modern styling) but the two halves are integrated well. I was assigned a Junior Suite (Globalist upgrade) in the new portion of the hotel. The "suite" was a single fairly large room (~450 sq ft) with a separate bathroom. Bathroom amenities were Beekman 1802. I found the decor both in the room and throughout the hotel quite pleasing. There are some attractive sitting areas on the ground floor, in particular. There are also some nice-looking conference facilities.

I agree that there is some street noise at this hotel from Main Street, and in addition the railroad tracks that parallel highway 99 are about 4 blocks away and there are many audible trains through both day and night. The outside noises aren't loud --- someone must have thought a little bit about sound mitigation during development, at least --- but they are audible. Sleepers who are sensitive to noise will definitely notice. Additionally, the hotel is a U shape, with a courtyard in the middle of the U where small bites and drinks are served and people congregate. Because of the U shape, many of the rooms necessarily face the courtyard, and some talking and music piped into the courtyard can be heard in your room until the courtyard shuts down at ~9pm.

The Globalist breakfast benefit was in the coffee shop ("Native Son") and I think it's $20 per person per day. I billed breakfast to my room and it was automatically removed from the bill at checkout without asking. In April the breakfast was take-away only. At night, the coffee shop turns into a bar which is open pretty late. The main restaurant isn't slated to open until the fall, I believe, but it looks fairly upscale (at least for Merced).

There aren't a ton of restaurants in Merced, though I do recommend the food at the Mainzer, which is a repurposed theater on the same block as the hotel and managed by the same outfit that manages the hotel. It's not considered a hotel restaurant, though, so no extra Hyatt points for spending money there. As is typical for the Central Valley, there are a number of good Mexican / Central American restaurants around town, though most of those are farther afield.

My reason for staying there was a simple change of scenery from my home office in the Bay Area, and it was just fine in that regard. No problems with the wifi in the room or outside in the courtyard. In fact, I spent one afternoon doing work while sitting at a table in the courtyard and the courtyard staff were happy to bring me water and whatever else I needed.